| 1. |
- Elowsson, Anders
(författare)
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Modeling Music : Studies of Music Transcription, Music Perception and Music Production
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This dissertation presents ten studies focusing on three important subfields of music information retrieval (MIR): music transcription (Part A), music perception (Part B), and music production (Part C).In Part A, systems capable of transcribing rhythm and polyphonic pitch are described. The first two publications present methods for tempo estimation and beat tracking. A method is developed for computing the most salient periodicity (the “cepstroid”), and the computed cepstroid is used to guide the machine learning processing. The polyphonic pitch tracking system uses novel pitch-invariant and tone-shift-invariant processing techniques. Furthermore, the neural flux is introduced – a latent feature for onset and offset detection. The transcription systems use a layered learning technique with separate intermediate networks of varying depth. Important music concepts are used as intermediate targets to create a processing chain with high generalization. State-of-the-art performance is reported for all tasks.Part B is devoted to perceptual features of music, which can be used as intermediate targets or as parameters for exploring fundamental music perception mechanisms. Systems are proposed that can predict the perceived speed and performed dynamics of an audio file with high accuracy, using the average ratings from around 20 listeners as ground truths. In Part C, aspects related to music production are explored. The first paper analyzes long-term average spectrum (LTAS) in popular music. A compact equation is derived to describe the mean LTAS of a large dataset, and the variation is visualized. Further analysis shows that the level of the percussion is an important factor for LTAS. The second paper examines songwriting and composition through the development of an algorithmic composer of popular music. Various factors relevant for writing good compositions are encoded, and a listening test employed that shows the validity of the proposed methods.The dissertation is concluded by Part D - Looking Back and Ahead, which acts as a discussion and provides a road-map for future work. The first paper discusses the deep layered learning (DLL) technique, outlining concepts and pointing out a direction for future MIR implementations. It is suggested that DLL can help generalization by enforcing the validity of intermediate representations, and by letting the inferred representations establish disentangled structures supporting high-level invariant processing. The second paper proposes an architecture for tempo-invariant processing of rhythm with convolutional neural networks. Log-frequency representations of rhythm-related activations are suggested at the main stage of processing. Methods relying on magnitude, relative phase, and raw phase information are described for a wide variety of rhythm processing tasks.
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| 2. |
- Bresin, Roberto, et al.
(författare)
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Sound and Music Computing at KTH
- 2012
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Ingår i: Trita-TMH. - Stockholm : KTH Royal Institute of Technology. - 1104-5787. ; 52:1, s. 33-35
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The SMC Sound and Music Computing group at KTH (formerly the Music Acoustics group) is part of the Department of Speech Music and Hearing, School of Computer Science and Communication. In this short report we present the current status of the group mainly focusing on its research.
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| 3. |
- Bresin, Roberto, et al.
(författare)
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Sound and Music Computing at KTH
- 2012
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Ingår i: SMC Sweden 2012 Sound and Music Computing, Understanding and Practicing in Sweden. - Stockholm : Department of Speech, Music and Hearing, Royal Institute of Technology. ; , s. 33-35
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Konferensbidrag (refereegranskat)
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| 4. |
- Askenfelt, Anders
(författare)
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Between the frog and the tip : Bowing gestures and bow-string interaction in violin playing (invited)
- 2008
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Ingår i: Program abstracts for Acoustics‘08 Paris. - : Acoustical Society of America (ASA). ; , s. 3656-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The motion of the bow gives a natural visualization of a string performance. Watching the player's bowing may augment the communicative power of the music, but all relevant bow control parameters are not easy to capture by a spectator. The string player controls volume of sound and tone quality continuously by coordination of three basic bowing parameters (bow velocity, bow‐bridge distance, and bow force), which set the main conditions for the bow‐string interaction. At a more detailed level of description, the tilting of the bow, which among other things controls the effective width of the bow hair, enters into the model. On a longer time scale, pre‐planned coordination schemes ('bowing gestures'), including the basic bowing parameters and the angles between the path of the bow and the strings, builds the performance. Systems for recording bowing parameters will be reviewed and results from old and current studies on bowing gestures presented. The player's choice and coordination of bowing parameters are constrained both in attacks and 'steady‐state' according to bow‐string interaction models. Recent verifications of these control spaces will be examined. Strategies for starting notes and examples of how players do in practice will be presented and compared with listeners' preferences.
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| 5. |
- Askenfelt, Anders
(författare)
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Double Bass
- 2010
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Ingår i: The Science of String Instruments. - New York, NY : Springer-Verlag New York. - 9781441971098 ; , s. 259-277
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Bokkapitel (refereegranskat)abstract
- The study of the acoustics of bowed instruments has for several reasons focused on the violin. A substantial amount of knowledge has been accumulated over the last century (see Hutchins 1975, 1976; Hutchins and Benade 1997). The violin is discussed in Chap. 13, while the cello is discussed in Chap. 14. The bow is discussed in Chap. 16.
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| 6. |
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| 7. |
- Askenfelt, Anders, et al.
(författare)
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Stage floor vibrations and bass sound in concert halls
- 2013
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Ingår i: Proceedings of Meetings on Acoustics. - : Acoustical Society of America (ASA). ; , s. 015028-
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Konferensbidrag (refereegranskat)abstract
- The double bass and cello sections in the orchestra transmit vibrations to the stage floor through the end pins. Whether or not these vibrations may contribute to the perceived sound in the hall has been investigated since the 1930s. In this study the conditions for an efficient transfer of instrument vibrations to the floor, as well as the radiation from the floor to the audience area, are investigated. The study includes measurements of the impedance matching between bass and stage floor, the vibration velocity transfer to the floor via the endpin, and radiation from point-driven bending waves in the stage floor well below the coincidence frequency. The impedance conditions and radiation properties of the stage floors of five concert halls were investigated. In the two most promising halls, full-scale experiments were run with an artificially excited double bass supported via the end pin on the stage floor and on a concrete support below, respectively. The contribution from the stage floor radiation to the sound level in the audience area was 5 dB or more between 30 and 60 Hz. This range covers the fundamental frequencies over one octave starting from the lowest note (B0) of a five-string bass.
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| 8. |
- Askenfelt, Anders, et al.
(författare)
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Study of the spectral inharmonicity of musical sound by the algorithms of pitch extraction
- 2000
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Ingår i: Acoustical Physics. - : Pleiades Publishing Ltd. - 1063-7710 .- 1562-6865. ; 46:2, s. 121-132
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Tidskriftsartikel (refereegranskat)abstract
- The algorithms of pitch extraction are widely used in the studies of signals and, specifically, speech signals for the determination of the fundamental frequency. From the previous studies performed by Galembo and the calculations and experiments described in this paper, it follows that these methods can be adapted for the analysis and evaluation of the factors which form the sound property called pitch strength, pitch salience, or intonation clarity. Although this property plays an important role in music, it is quite poorly investigated. One of the aforementioned factors is represented by the distributed spectral inharmonicity which is typical of sounds produced, e.g., by strings. This paper presents a method of visualization, evaluation, and measurement of the inharmonicity of the spectrum of a musical sound with the help of the well-known algorithms of pitch extraction, namely the cepstrum and the harmonic product spectrum.
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| 9. |
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| 10. |
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| 11. |
- Björkner, Eva
(författare)
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Why so different? - Aspects of voice characteristics in operatic and musical theatre singing : Aspects of voice characteristics in operatic and musical theatre singing
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis addresses aspects of voice characteristics in operatic and musical theatre singing. The common aim of the studies was to identify respiratory, phonatory and resonatory characteristics accounting for salient voice timbre differences between singing styles.The velopharyngeal opening (VPO) was analyzed in professional operatic singers, using nasofiberscopy. Differing shapes of VPOs suggested that singers may use a VPO to fine-tune the vocal tract resonance characteristics and hence voice timbre. A listening test revealed no correlation between rated nasal quality and the presence of a VPO.The voice quality referred to as “throaty”, a term sometimes used for characterizing speech and “non-classical” vocalists, was examined with respect to subglottal pressure (Psub) and formant frequencies. Vocal tract shapes were determined by magnetic resonance imaging. The throaty versions of four vowels showed a typical narrowing of the pharynx. Throatiness was characterized by increased first formant frequency and lowering of higher formants. Also, voice source parameter analyses suggested a hyper-functional voice production.Female musical theatre singers typically use two vocal registers (chest and head). Voice source parameters, including closed-quotient, peak-to-peak pulse amplitude, maximum flow declination rate, and normalized amplitude quotient (NAQ), were analyzed at ten equally spaced subglottal pressures representing a wide range of vocal loudness. Chest register showed higher values in all glottal parameters except for NAQ. Operatic baritone singer voices were analyzed in order to explore the informative power of the amplitude quotient (AQ), and its normalized version NAQ, suggested to reflect glottal adduction. Differences in NAQ were found between fundamental frequency values while AQ was basically unaffected.Voice timbre differs between musical theatre and operatic singers. Measurements of voice source parameters as functions of subglottal pressure, covering a wide range of vocal loudness, showed that both groups varied Psub systematically. The musical theatre singers used somewhat higher pressures, produced higher sound pressure levels, and did not show the opera singers’ characteristic clustering of higher formants.Musical theatre and operatic singers show highly controlled and consistent behaviors, characteristic for each style. A common feature is the precise control of subglottal pressure, while laryngeal and vocal tract conditions differ between singing styles. In addition, opera singers tend to sing with a stronger voice source fundamental than musical theatre singers.
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| 12. |
- Dahl, Sofia, 1972-
(författare)
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On the beat : human movement and timing in the production and perception of music
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis addresses three aspects of movement, performance and perception in music performance. First, the playing of an accent, a simple but much used and practiced element in drumming is studied, second, the perception of gradually changing tempo, and third, the perception and communication of specific emotional intentions through movements during music performance. Papers I and II investigated the execution and interpretation of an accent in drumming, performed under different playing conditions. Players' movements, striking velocities and timing patterns were studied for different tempi, dynamic levels and striking surfaces. It was found that the players used differing movement strategies and that interpreted the accent differently, reflected in their movement trajectories. Strokes at higher dynamic levels were played from a greater average height and with higher striking velocities. All players initiated the accented strokes from a greater height, and delivered the accent with increased striking velocity compared to the unaccented strokes. The interval beginning with the accented stroke was also prolonged, generally by delaying the following stroke. Recurrent cyclic patterns were found in the players' timing performances. In a listening test, listeners perceived grouping of the strokes according to the cyclic patterns. Paper III concerned the perception of gradual tempo changes in auditory sequences. Using an adaptive test procedure subjects judged stimuli consisting of click sequences with either increasing or decreasing tempo, respectively. Each experiment included three test sessions at different nominal tempi (80, 120, and 180~beats per minute). The results showed that ten of the eleven subjects showed an inherent bias in their perception of tempo drift. The direction and magnitude of the bias was consistent between test sessions but varied between individuals. The just noticeable differences for tempo drift agreed well with the estimated tempo drifts in production data, but were much smaller than earlier reported thresholds for tempo drift. Paper IV studied how emotional intent in music performances is conveyed to observers through the movements of the musicians. Three players of marimba, bassoon, and saxophone respectively, were filmed when playing with the expressive intentions Happiness, Sadness, Anger and Fear. Observers rated the emotional content and movement cues in the videos clips shown without sound. The results showed that the observers were able to identify the intentions Sadness, Anger, and Happiness, but not Fear. The rated movement cues showed that an Angry performance was characterized by jerky movements, Happy performances by large, and somewhat fast and jerky movements, and Sad performances by slow, and smooth movements.
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| 13. |
- Demoucron, Matthias, et al.
(författare)
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Measuring Bow Force in Bowed String Performance : Theory and Implementation of a Bow Force Sensor
- 2009
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Ingår i: Acta Acoustica united with Acustica. - 1610-1928 .- 1861-9959. ; 95:4, s. 718-732
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Tidskriftsartikel (refereegranskat)abstract
- A sensor has been developed which allows measurement of the force exerted by the bow on the string ( bow force) during violin performance. The bow force is deduced from measurement of the transversal force at the termination of the bow hair at the frog. The principle is illustrated with an experiment that demonstrates how the bending of the stick and variations in bow hair tension influence the measurements. The design of the sensor is described and performance characteristics are discussed. A thorough calibration procedure is described and tested. Finally, the use of the sensor is demonstrated through measurements in real playing situations.
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| 14. |
- Demoucron, Matthias, 1980-
(författare)
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On the control of virtual violins : Physical modelling and control of bowed string instruments
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis treats the control of sound synthesis of bowed string instruments based on physical modelling. The work followed two approaches: (a) a systematic exploration of the influence of control parameters (bow force, bow velocity, and bow-bridge distance) on the output of a physical model of the violin, and (b) measurements and analyses of the bowing parameters in real violin playing in order to model and parameterize basic classes of bowing patterns for synthesis control.First a bowed-string model based on modal solutions of the string equation is described and implemented for synthesis of violin sounds. The behaviour of the model is examined through simulations focusing on playability, i.e. the control parameter space in which a periodic Helmholtz motion is obtained, and the variations of the properties of the simulated sound (sound level and spectral centroid) within this parameter space. The response of the model corresponded well with theoretical predictions and empirical expectations based on observations of real performances. The exploration of the model allowed to define optimal parameter regions for the synthesis, and to map sound properties on the control parameters.A second part covers the development of a sensor for measuring the bow force in real violin performance. The force sensor was later combined with an optical motion capture system for measurement of complete sets of bowing parameters in violin performance.In a last part, measurements of the control parameters for basic classes of bowing patterns (sautillé, spiccato, martelé, tremolo) are analyzed in order to propose a realistic control of the sound synthesis. The time evolution of the bowing parameters were modelled by analytical functions, which allowed to describe and control simulated bowing patterns by a limited set of control parameters. For sustained bowing patterns such as détaché, control strategies for basic elements in playing (variations in dynamic level, bow changes) were extracted from exemplary measurements, and simple rules deduced, which allowed extrapolation of parameters to modified bow strokes with other durations and at different dynamic levels.
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| 15. |
- Enlund, Nils, et al.
(författare)
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Mediated masterclass teaching
- 2007
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Ingår i: Proc. of Developing Innovative Video Resources for Students Everywhere. - Lillehammer : Høgskolen i Lillehammer.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 16. |
- Fober, D., et al.
(författare)
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IMUTUS : an interactive music tuition system
- 2004
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Ingår i: Proc. of the Sound and Music Computing Conference (SMC 04), October 20-22, 2004, IRCAM, Paris, France. ; , s. 97-103
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 17. |
- Galembo, A., et al.
(författare)
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Effects of relative phases on pitch and timbre in the piano bass range
- 2001
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Ingår i: Journal of the Acoustical Society of America. - : Acoustical Society of America (ASA). - 0001-4966 .- 1520-8524. ; 110:3, s. 1649-1666
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Tidskriftsartikel (refereegranskat)abstract
- Piano bass tones raise questions related to the perception of multicomponent, inharmonic tones. In this study, the influence of the relative phases among partials on pitch and timbre was investigated for synthesized bass tones with piano-like inharmonicity. Three sets of bass tones (A0 = 27.5 Hz, 100 partials, flat spectral envelope) were generated; harmonic, low inharmonic, and high inharmonic. For each set, five starting phase relations among partials were applied; sine phases, alternate (sine/cosine) phases, random phases, Schroeder phases, and negative Schroeder phases. The pitch and timbre of the tones were influenced markedly by the starting phases. Listening tests showed that listeners are able to discriminate between tones having different starting phase relations, and also that the pitch could be changed by manipulating the relative phases (octave, fifth, major third). A piano-like inharmonicity gives a characteristic randomizing effect of the phase relations over time in tones starting with nonrandom phase relations. A measure of the regularity of the phase differences between adjacent partials is suggested for quantifying this randomization process. The observed phase effects might be of importance in synthesizing, recording, and reproducing piano music.
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| 18. |
- Galembo, A., et al.
(författare)
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Perceptual relevance of inharmonicity and spectral envelope in the piano bass range
- 2004
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Ingår i: Acta Acoustica united with Acustica. - 1610-1928 .- 1861-9959. ; 90:3, s. 528-536
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Tidskriftsartikel (refereegranskat)abstract
- Professionals consider the differences in the timbre of bass tones between large grand pianos and small uprights as significant. By tradition this difference has been attributed mainly to lower inharmonicity in grand pianos, due to longer bass strings. In this study, the importance of the spectral envelope, representing the dynamic balance between high-frequency and low-frequency energy in the spectrum, is contrasted against the importance of the level of inharmonicity. Results from two listening tests indicate that the inharmonicity is less important than the spectrum bandwidth in determining the timbre of piano bass tones.
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| 19. |
- Galembo, A. S., et al.
(författare)
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Overlapping of sounds in piano passages
- 2006
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Ingår i: Acoustical Physics. - : Pleiades Publishing Ltd. - 1063-7710 .- 1562-6865. ; 52:2, s. 144-150
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Tidskriftsartikel (refereegranskat)abstract
- It is well known that, in piano passages, specifically, in those played legato, sounds may overlap in time. Our experiments show that this overlapping is much greater than one would expect proceeding from the undistorted pitch perception in a given phrase. Moreover, the sounds produced by piano and perceived by a listener as clearly distinguished in pitch, when subjected to an objective analysis, may prove to be a mixture of equally intense components of the preceding and next sounds. This phenomenon is related to the problem of piano quality, including the still unclarified role of the damper system, as well as to the mysterious manifestation of pianist's personality that is called the art of touch.
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| 20. |
- Guettler, K., et al.
(författare)
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An in-depth analysis of the double bass to stage floor contact
- 2008
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Ingår i: Proc. of Auditorium Acoustics 2008, 3-5 October 2008, Oslo, Norway. - : Institute of Acoustics. - 9781605605395 ; , s. 37-44
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- While double bassists claim the importance of compliant floors for producing a warm and nuanced sound, the scarce research focusing on this topic has left few conclusions. In the mean time stage floors are constructed with great spread in design and conviction. In the present project floors of several halls were analysed, including the Oslo Concert Hall and Oslo's new Opera House. It was found that in the range where the double bass radiates poorly, i.e., below 100 Hz, and in particular below its Helmholtz resonance at ca 60 Hz, a favourable coupling can take place when the floor is compliant. In such cases the velocity transfer from the instrument's bridge to the floor (via the corpus and end pin) may often rise significantly above zero dB. The coupling, bass to floor, was also seen to affect the bridge mobility and thus the playing properties of the instrument. In the same frequency range the power transfer was observed to boost from about 3 to 40%. It remains to investigate how noticeable this effect is to the audience. Our measurements indicate, however, that a coupling to the stage floor can make an audible difference to the player.
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| 21. |
- Guettler, K., et al.
(författare)
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Double basses on the stage floor : Tuning fork–table top effect or not?
- 2012
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Ingår i: Journal of the Acoustical Society of America. - : Acoustical Society of America (ASA). - 0001-4966 .- 1520-8524. ; 131:1, s. 795-806
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Tidskriftsartikel (refereegranskat)abstract
- The question whether or not double basses can benefit from a compliant and radiating stage floor in the low end of their tonal register, similar to the well-known tuning fork–tabletop effect, was examined through field experiments in five concert halls. The topic comprises several aspects: (1) How well the mechanical impedances of double basses and the stage floor match, (2) amount of vibration velocity transmitted to the floor through the end pin of the bass, and (3) radiation efficiency of point-excited bending waves in the stage floor far below the coincidence frequency. Each aspect represents a prerequisite for the tuning fork–tabletop effect to take place. The input impedance at the end pin was measured for three representative double basses. The stage floors of five orchestra halls were measured with respect input impedance and damping, while sound radiation to the audience area was measured for two of them. In Lindeman Hall, Oslo, all conditions for the tuning fork–tabletop effect to take place were clearly met. The contribution from the stage-floor radiation to the sound pressure level in the audience area was found to be about 5 dB between 40 and 60 Hz, and even higher between 30 and 40 Hz.
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| 22. |
- Guettler, K., et al.
(författare)
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Double basses on the stage floor
- 2007
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Ingår i: Proc. of International Symposium on Musical Acoustics (ISMA 2007), September 9-21, 2007, Barcelona, Spain. ; , s. paper 3-P1
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 23. |
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| 24. |
- Guettler, K., et al.
(författare)
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The Lindeman Hall of Oslo - Evidence of low-frequency radiation from the stage floor
- 2010
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Ingår i: 20th International Congress on Acoustics 2010, ICA 2010 - Incorporating Proceedings of the 2010 Annual Conference of the Australian Acoustical Society. - 9781617827457 ; , s. 2329-2334
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Konferensbidrag (refereegranskat)abstract
- It is well known that plate radiation below the critical frequency is very poor, and therefore many stage floors dissipate low-frequency energy transmitted from double-bass and cello end pins rather than providing a tuning-fork/tabletop effect. However, if the stage floor is well damped, so that the transverse amplitudes fade out quickly around the point of excitation, a significant net radiation can be experienced also for low frequencies, due to the piston/baffle effect. Measurements performed in the Lindeman Hall of the Norwegian Academy of Music, in Oslo, Norway, showed that vibrational amplitudes in the stage floor faded out at a nearly equal pace in all directions around the excitation points, leaving nearly circular, quasi isotropic patterns for most frequencies of interest. In the audience area no tendency of spectral roll off was seen in the low-frequency end down to 30 Hz, which may represent the lowest fundamental of modern double basses. Transfer functions from stage floor to audience (intensity vs. power, and sound pressure vs. transverse velocity) were calculated for a number of seats in the hall.
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| 25. |
- Lehtonen, Heidi-Maria, et al.
(författare)
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Analysis of the part-pedaling effect in the piano
- 2009
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Ingår i: Journal of the Acoustical Society of America. - : Acoustical Society of America (ASA). - 0001-4966 .- 1520-8524. ; 126:2, s. EL49-EL54
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Tidskriftsartikel (refereegranskat)abstract
- This letter reports basic acoustic phenomena related to part-pedaling in the piano. With part-pedaling, the piano tone can be divided into three distinct time intervals: initial free vibration, damper-string interaction, and final free vibration. Varying the distance of the damper from the string, the acoustic signal and the damper acceleration were measured for several piano tones. During the damper-string interaction, the piano tone decay is rapid and the timbre of the tone is affected by the nonlinear amplitude limitation of the string motion. During the final free decay, the string continues to vibrate freely with a lower decay rate.
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| 26. |
- Nilsonne, Åsa, et al.
(författare)
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Measuring the rate of change of voice fundamental frequency in fluent speech during mental depression
- 1988
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Ingår i: The Journal of the Acoustical Society of America. - : American Institute of Physics (AIP). - 0001-4966. ; 83:2, s. 716-728
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Tidskriftsartikel (refereegranskat)abstract
- A method of measuring the rate of change of fundamental frequency has been developed in an effort to find acoustic voice parameters that could be useful in psychiatric research. A minicomputer program was used to extract seven parameters from the fundamental frequency contour of tape‐recorded speech samples: (1) the average rate of change of the fundamental frequency and (2) its standard deviation, (3) the absolute rate of fundamental frequency change, (4) the total reading time, (5) the percent pause time of the total reading time, (6) the mean, and (7) the standard deviation of the fundamental frequency distribution. The method is demonstrated on (a) a material consisting of synthetic speech and (b) voice recordings of depressed patients who were examined during depression and after improvement.
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| 27. |
- Raptis, S., et al.
(författare)
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IMUTUS – An effective practicing environment for music tuition
- 2005
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Ingår i: Proc. of International Computer Music Conference (ICMC 2005). - : International Computer Music Association. ; , s. 383-386
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Konferensbidrag (refereegranskat)abstract
- This paper presents some major results from the IMUTUS project. IMUTUS was an RTD project that aimed at the development of an open platform for training students on the recorder. The paper focuses on one of the most important and innovative parts of the IMUTUS system, the practicing environment. This environment integrates technological tools for the automatic analysis and evaluation of student performances along with enhanced interaction schemes to provide an effective approach to music learning. Testing and validation activities that have been carried out indicate that the IMUTUS approach is appreciated by both students and teacher, and that it clearly has a strong potential.
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| 28. |
- Schoonderwaldt, Erwin, 1973-, et al.
(författare)
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An empirical investigation of bow-force limits in the Schelleng diagram
- 2008
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Ingår i: Acta Acoustica united with Acustica. - 1610-1928 .- 1861-9959. ; 94:4, s. 604-622
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Tidskriftsartikel (refereegranskat)abstract
- An experimental study of the upper and lower bow-force limits for bowed violin strings is reported. A bowing machine was used to perform bow strokes with a real violin bow on steel D and E strings mounted on a rigid monochord and on a violin. Measurements were systematically performed for 11 values of relative bow-bridge distance and 24 values of bow force at four bow velocities (5, 10, 15 and 20 cm/s). The measured string velocity signals were used to compile Schelleng diagrams, showing the distribution of different classes of string motion (multiple slipping, Helmholtz motion, raucous motion). It was found that the maximum bow-force limit for Helmholtz motion corresponded well to Schelleng's equation in modified form, taking the shape of the (hyperbolic) friction curve into account. The minimum bow force was found to be independent of bow velocity, which is in clear contradiction to Schelleng's prediction. Observations and simulations suggested that the breakdown of Helmholtz motion at low bow forces involves a mechanism related to ripple and corner rounding which was not taken into account in Schelleng's derivation of minimum bow force. The influence of damping showed only qualitative agreement with Schelleng's predictions.
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| 29. |
- Schoonderwaldt, Erwin, et al.
(författare)
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Design and implementation of automatic evaluation of recorder performance in IMUTUS
- 2005
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Ingår i: Proc. of International Computer Music Conference (ICMC 2005). - : International Computer Music Association. ; , s. 431-434
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Konferensbidrag (refereegranskat)abstract
- This paper describes a novel approach towards automatic evaluation of recorder performance. The processes from finding errors to the formulation of feedback are based on analyses of student performances and experience of recorder teachers. The developed algorithms were implemented in IMUTUS, a prototype practising environment for the recorder.
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| 30. |
- Schoonderwaldt, Erwin, et al.
(författare)
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IMUTUS : an interactive system for learning to play a musical instrument
- 2004
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Ingår i: Proc. of International Conference of Interactive Computer Aided Learning (ICL), September 29 - October 1, 2004, Carinthia Tech Institute, Villach, Austria. - : Kassel University Press GmbH.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- IMUTUS (Interactive Music Tuition System) is a EU project that aims to develop a practising environment for the recorder, combining new technologies and new approaches for music learning. Automatic analysis and evaluation of student performances play a central role in the student-system interaction. The performance evaluation module identifies typical performance errors, and provides feedback that relates to performance skills, helping the student to improve. The performance evaluation process is based on the knowledge and experience of recorder teachers, obtained via questionnaires, interviews and structured evaluations of recorded student performances. Another important feature of the performance evaluation is that it can be guided by teachers writing the content for IMUTUS by means of annotations.
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| 31. |
- Schoonderwaldt, Erwin, 1973-
(författare)
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Mechanics and acoustics of violin bowing : Freedom, constraints and control in performance
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis addresses sound production in bowed-string instruments from two perspectives: the physics of the bowed string, and bow control in performance. Violin performance is characterized by an intimate connection between the player and the instrument, allowing for a continuous control of the sound via the main bowing parameters (bow velocity, bow force and bow-bridge distance), but imposing constraints as well. In the four included studies the focus is gradually shifted from the physics of bow-string interaction to the control exerted by the player. In the first two studies the available bowing parameter space was explored using a bowing machine, by systematically probing combinations of bow velocity, bow force and bow-bridge distance. This allowed for an empirical evaluation of the maximum and minimum bow force required for the production of a regular string tone, characterized by Helmholtz motion. Comparison of the found bow-force limits with theoretical predictions by Schelleng revealed a number of striking discrepancies, in particular regarding minimum bow force. The observations, in combination with bowed-string simulations, provided new insights in the mechanism of breakdown of Helmholtz motion at low bow forces. In the second study the influence of the main bowing parameters on aspects of sound quality was analyzed in detail. It was found that bow force was totally dominating the control of the spectral centroid, which is related to the perceived brightness of the tone. Pitch flattening could be clearly observed when approaching the upper bow-force limit, confirming its role as a practical limit in performance. The last two studies were focused on the measurement of bowing gestures in violin and viola performance. A method was developed for accurate and complete measurement of the main bowing parameters, as well as the bow angles skewness, inclination and tilt. The setup was used in a large performance study. The analyses revealed clear strategies in the use of the main bowing parameters, which could be related to the constraints imposed by the upper and lower bow-force limits and pitch flattening. Further, it was shown that two bow angles (skewness and tilt) were systematically used for controlling dynamic level; skewness played an important role in changing bow-bridge distance in crescendo and diminuendo notes, and tilt was used to control the gradation of bow force. Visualizations and animations of the collected bowing gestures revealed significant features of sophisticated bow control in complex bowing patterns.
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| 32. |
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| 33. |
- Tambouratzis, G., et al.
(författare)
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VEMUS: An integrated platform to support music tuition tasks
- 2008
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Ingår i: 8TH IEEE INTERNATIONAL CONFERENCE ON ADVANCED LEARNING TECHNOLOGIES, PROCEEDINGS. - : IEEE Computer Society. - 9780769531670 ; , s. 972-976
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Konferensbidrag (refereegranskat)abstract
- In this paper, the VEMUS platform is presented, as a novel approach for music tuition that focuses on beginner and intermediate students, typically aged from 9 to 15 years. This platform is characterized by an open, highly interactive and networked multilingual music tuition framework that covers a selection of popular wind instruments. The VEMUS environment integrates innovative, pedagogically-motivated e- learning components to augment traditional music teaching in three distinct learning settings, namely self-practicing, classroom and distance learning. In the present article, the current stage of development of VEMUS is presented, and the areas where it might be of most use towards supporting the educational activities associated with music tuition are identified.
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| 34. |
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| 35. |
- Öberg, Fredrik, et al.
(författare)
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Acoustical and perceptual influence of duplex stringing in grand pianos
- 2012
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Ingår i: Journal of the Acoustical Society of America. - : Acoustical Society of America (ASA). - 0001-4966 .- 1520-8524. ; 131:1, s. 856-871
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Tidskriftsartikel (refereegranskat)abstract
- This study investigates the acoustical and perceptual influence of the string parts outside the speaking length in grand pianos (front and rear duplex strings). Acoustical measurements on a grand piano in concert condition were conducted, measuring the fundamental frequencies of all main and duplex strings in the four octaves D4-C8. Considerable deviations from the nominal harmonic relations between the rear duplex and main string frequencies, as described by the manufacturer in a patent, were observed. Generally the rear duplex strings were tuned higher than the nominal harmonic relations with average and median deviations approaching _50 cent. Single keys reached +190 and -100 cent. The spread in deviation from harmonic relations within trichords was also substantial with average and median values around 25 cent, occasionally reaching 60 cent. Contributions from both front and rear duplex strings were observed in the bridge motion and sound. The audibility of the duplex strings was studied in an ABX listening test. Complete dampening of the front duplex was clearly perceptible both for an experiment group consisting of musicians and a control group with naive subjects. The contribution from the rear duplex could also be perceived, but less pronounced.
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