Timbre Variations Research Articles

Timbral Virtuosity: Pharoah Sanders, Sonic Heterogeneity, and the Jazz Avant-garde in the 1960s and 70s

Saxophonist, composer, and bandleader Pharoah Sanders is best known for recording a handful of meditative, cosmologically-inclined free jazz classics from the 1960s and 1970s, including “The Creator Has a Master Plan.” This article looks at the reasons for these recordings' popularity at the time, arguing that the key to understanding these works can be found in Sanders's use of timbral variation as a formal element. In considering what I call “timbral virtuosity” in Sanders's work, this article discusses the relationships that such a focus allows us to more clearly see between avant-garde jazz, fusion, and contemporaneous popular music from rock to soul.

Mislateralization of sound images at dichotically presented a rippled noise signal and masker

A mislateralization effect was observed when a target signal and a masker were presented dichotically: the target signal in one ear and the masker in the other ear. The target signal was band-filtered rippled noise with periodical interchange of ripple peaks and troughs positions. This interchange produced periodical timbre variations in the sound image. The masker was non-rippled band-filtered noise. In 100% of the trials, the image of periodical variations of timbre reflecting interchanges of the ripple peaks and troughs in the target signal was perceived (released from masking) at low ripple density and signal/masker ratios down to -35 dB. However, lateralization of the image depended on the signal/masker ratio. The image was correctly lateralized toward the ear of the target signal when the signal was of a higher level than the masker. The image was wrongly lateralized toward the ear of the masker presentation (mislateralized) when the masker was of a higher level than the signal. Implications to mechanisms of dichotic release from masking are discussed: the release is possible without the spatial-attention mechanism.

Pitch and Timbre Interfere When Both Are Parametrically Varied

Pitch and timbre perception are both based on the frequency content of sound, but previous perceptual experiments have disagreed about whether these two dimensions are processed independently from each other. We tested the interaction of pitch and timbre variations using sequential comparisons of sound pairs. Listeners judged whether two sequential sounds were identical along the dimension of either pitch or timbre, while the perceptual distances along both dimensions were parametrically manipulated. Pitch and timbre variations perceptually interfered with each other and the degree of interference was modulated by the magnitude of changes along the un-attended dimension. These results show that pitch and timbre are not orthogonal to each other when both are assessed with parametrically controlled variations.

From sound to shape: Auditory perception of drawing movements.

This study investigates the human ability to perceive biological movements through friction sounds produced by drawings and, furthermore, the ability to recover drawn shapes from the friction sounds generated. In a first experiment, friction sounds, real-time synthesized and modulated by the velocity profile of the drawing gesture, revealed that subjects associated a biological movement to those sounds whose timbre variations were generated by velocity profiles following the 1/3 power law. This finding demonstrates that sounds can adequately inform about human movements if their acoustic characteristics are in accordance with the kinematic rule governing actual movements. Further investigations of our ability to recognize drawn shapes were carried out in 2 association tasks in which both recorded and synthesized sounds had to be associated to both distinct and similar visual shapes. Results revealed that, for both synthesized and recorded sounds, subjects made correct associations for distinct shapes, although some confusion was observed for similar shapes. The comparisons made between recorded and synthesized sounds lead to conclude that the timbre variations induced by the velocity profile enabled the shape recognition. The results are discussed in the context of the ecological and ideomotor frameworks.

Preattentive processing of emotional musical tones: a multidimensional scaling and ERP study

Musical emotion can be conveyed by subtle variations in timbre. Here, we investigated whether the brain is capable to discriminate tones differing in emotional expression by recording event-related potentials (ERPs) in an oddball paradigm under preattentive listening conditions. First, using multidimensional Fechnerian scaling, pairs of violin tones played with a happy or sad intonation were rated same or different by a group of non-musicians. Three happy and three sad tones were selected for the ERP experiment. The Fechnerian distances between tones within an emotion were in the same range as the distances between tones of different emotions. In two conditions, either 3 happy and 1 sad or 3 sad and 1 happy tone were presented in pseudo-random order. A mismatch negativity for the emotional deviant was observed, indicating that in spite of considerable perceptual differences between the three equiprobable tones of the standard emotion, a template was formed based on timbral cues against which the emotional deviant was compared. Based on Juslin's assumption of redundant code usage, we propose that tones were grouped together, because they were identified as belonging to one emotional category based on different emotion-specific cues. These results indicate that the brain forms an emotional memory trace at a preattentive level and thus, extends previous investigations in which emotional deviance was confounded with physical dissimilarity. Differences between sad and happy tones were observed which might be due to the fact that the happy emotion is mostly communicated by suprasegmental features.

Differences in instrument construction and performance practices among musical traditions reveal and guide different aesthetic attitudes towards timbre

Musical aesthetic judgments reflect how each musical tradition chooses to interpret and value contextual, functional, performance, formal, and sonic aspects of musical pieces. Elaborate instrument construction techniques and performance practices devoted to the exploration of timbre (sound color) variations across musical traditions indicate that timbre is a sonic aspect on which musical aesthetic judgments are often based. Intercultural differences and intra-cultural consistency of timbre interpretation illustrate the cultural bases of understanding and evaluating sound color. Close examination of musical instrument construction and performance practices, accompanied by acoustical analyses of the relevant sound signals, can reveal the types of musical timbres and timbre variation degrees a given tradition is after, providing insights on the relationship between timbre and a tradition's musical aesthetic values. The sophisticated ways devised to produce and manipulate auditory roughness within the musical contexts addressed in this presentation (Indian tambura accompaniments; Middle Eastern mijwiz improvisations; Bosnian ganga songs) will be contrasted to the limited opportunities for such explorations afforded within western art musical contexts, paralleled by equally contrasting aesthetic attitudes towards auditory roughness's meaning and value.

The Ethiopian lyre Bagana. An ethno-acoustical study

The Ethiopian lyre bagana is usually finger-plucked and monodic, with a skin soundboard and ten gut strings tuned to low-frequency pitches (ca 50-150 Hz). Its most important sonorous characteristic is its buzzing sounds, produced thanks to leather pieces placed between each string and the wide bridge. This study is based on a corpus of sounds produced by eight different instruments played by a virtuoso master and recorded in situ with and without the leather pieces. The sounds have been analyzed through calculation of several timbre descriptors based on time-domain, sinusoidal harmonic model and short-time Fourier transform representations. These results have been compared with ethnomusicological analyses of the repertoire and the socio-cultural aspects of the bagana, in order to understand how the sound qualities are dealt with by the players. These joint analyses show that the very distinctive buzzing quality of the bagana sounds can be linked with auditory roughness and inharmonicity descriptors (indicating that it is not due to noise but rather to quasi-harmonic components) while the significant timbre variation between sounds is mostly due to differences in string quality, location of the leather pieces on the bridge and musicians' need to produce the longest possible duration.

Temporality in Musical Meaning: A Peircean/Deweyan Semiotic Approach

Imagine a single musical tone—for instance, the A above middle C that the oboe plays to tune an orchestra. Now imagine this tone, with no variation in dynamics, pitch, or timbre, extended over the course of “an hour or a day,” existing, as Peirce describes in “How to Make Our Ideas Clear” (W3:262),1 “as perfectly in each second of that time as in the whole taken together; so that, as long as it is sounding, it might be present to a sense from which everything in the past was as completely absent as the future itself ” (W3:262). Imagine a world consisting of nothing but the sensation of this single oboe A, and having never consisted of anything but it. In such a world, Peirce indicates, there would be no consciousness of the passage of time. It is indeed doubtful whether one would be conscious of the tone at all, since there would be no background of experience in terms of which to interpret the sound, either perceptually or rationally.2 Although the sound waves would register physically in the ear, the distinctive timbre of the oboe would not be perceived because there would be no experience of other timbres with which to compare it. The aural perception of a musical theme or a tune, on the other hand, is inexorably temporal. The performance of a tune unfolds over time. It “consists in an orderliness in the succession of sounds which strike the ear at different times; and to perceive it there must be some continuity of consciousness which makes the events of a lapse of time present to us” (W3:262). The physical sensation of each sound is “completely present at every instant” while it lasts, but the tune or theme—the music—is never given to consciousness as an unmediated presence. The “orderliness in the succession of sounds”—which

Influence of pitch, loudness, and timbre on the perception of instrument dynamics

The effect of variations in pitch, loudness, and timbre on the perception of the dynamics of isolated instrumental tones is investigated. A full factorial design was used in a listening experiment. The subjects were asked to indicate the perceived dynamics of each stimulus on a scale from pianissimo to fortissimo. Statistical analysis showed that for the instruments included (i.e., clarinet, flute, piano, trumpet, and violin) timbre and loudness had equally large effects, while pitch was relevant mostly for the first three. The results confirmed our hypothesis that loudness alone is not a reliable estimate of the dynamics of musical tones.

Rhythmic Archetypes in Instrumental Music from Africa and the Diaspora

[1] In this paper I will propose a method for analyzing the rhythmic organization of instrumental music in Africa and the Diaspora using a set of six rhythmic tropes I call rhythmic archetypes.(1) A rhythmic archetype is a commonly used rhythmic formula that exists on both the surface-structural level, occurring within various parts of a music ensemble, and the deep-structural level, where it serves as a prototype for a multitude of possible variations through changes in pitch, timbre, and rhythm. Rhythmic archetypes may be produced by individual parts or may emerge from the resultant texture of multiple parts. Those who play some form of African music will know and use patterns like these-in African-inspired popular music styles like jazz, salsa, and reggae, musicians give them names like tumbao, montuno, martillo, mambo, walking the bass, and one drop.(2) In Africa, rhythmic archetype patterns may not be given specific terms; instead, they are more often expressed by singing or playing the resultant combination they produce with the other parts.(3)[2] As I will discuss below, other researchers have observed some of these patterns within their areas of study, but to date they have not connected them with other African music traditions. Instead, the prevailing tendency has been to view the rhythmic archetypes examined below as rhythmic oddities, applying a host of terms such as additive rhythm, polymeter, and cross-rhythm to describe the supposed rhythmic tension they produce.(4) In this comprehensive study, however, I will demonstrate the recurrence of these six rhythmic archetype patterns in several African music traditions, documented here using over forty transcriptions and audio examples. Due to the ubiquity and regularity of these patterns, I will argue that rhythmic archetypes are not sources of rhythmic dissonance, but rather form a set of phrase-building blocks in many African music systems. I will further contend that phrases constructed using rhythmic archetypes cannot be analyzed outside of the complete rhythmic background where they typically occur, which would likely contain accompaniment of some sort such as dancing, singing and clapping. Recognizing this multi-sensorial perception of the rhythmic background within the minds of enculturated listeners,(5) I will argue that rhythmic archetypes enhance the effect of the metric background rather than disrupt or clash against it.[3] All six rhythmic archetypes have become widely distributed throughout Africa and the Black Atlantic. In defining and seeking out these patterns, I have combined fifteen years of experience learning and playing several African instruments with a detailed analytical survey of published music transcriptions from this region. Accounting for variations in pitch and timbre, I have discovered that these rhythmic archetypes outline an identifiable connection between the rhythmic systems of several African music traditions at both the surface- and deep-structural levels. This group of rhythmic archetypes does not appear to have developed at random; rather, I will argue that they developed out of a textural sense of rhythm that is based on an aesthetic preference, within a given African musical community, for particular combinations of interwoven parts. Each archetype relates to the compound metric background by dividing its time-points into subsets of equally spaced notes based on simple mathematical ratios. Thus, the rhythmic archetypes presented below can be said to represent the foundation of a Pan-African musical syntax, and hopefully the accompanying transcriptions and audio examples will prove useful to teachers and students of African music.[4] The six rhythmic archetypes form part of a larger theory of rhythmic archetypes, which is also concerned with the perception and representation of rhythmic figures in general within the performance and study of African music. …

Contextualizing eighteenth century Enlightenment through the lenses of contemporary science

Leonid Perlovsky’s hypothesis that music evolved from “a split in the vocalizations of proto-humans into two types: one less emotional and more concretely-semantic, evolving into language, and the other preserving emotional connections along with semantic ambiguity, evolving into music” bears remarkable resemblances to French Enlightenment philosophy [1]. It is surprising that classic philosophers such as Etienne Bonnot de Condillac and Jean-Jacques Rousseau were not cited in this paper. By the mid of the 1700s, in his Essai sur l’origine des connaissances humaines [2], Condillac depicted the earliest spoken languages as being composed of action-orientated vocal inflections such as warnings, cries for help and shouts of pleasure. They did not use consonants but vowel-like intonations. Condillac suggested that early hominids did not prioritize the invention of different utterances (or ‘words’), but tended to use a short repertoire of utterances with different variations in pitch and timbre in order to express different things. In contemporary music theory these variations are considered as important carriers of musical emotions. Also in the eighteenth century, Rousseau suggested that vocal utterances of early hominids expressed primarily feelings (e.g., “I am sad. . .”), whilst gestures were normally preferred to express rational thoughts (e.g., “Brrr. . . It is getting cold. Let’s make a fire!”). Like Condillac, Rousseau proposed that primeval languages might have sounded like melodies of vowel-like utterances. However, he offered an interesting explanation for the emergence of consonants: as hominids’ dealings with one another grew in complexity, spoken language needed to become less passionate and more precise. In his Essai sur l’origine des langues [3], Rousseau argued that the emergence of sophisticated languages was motivated by the increasing necessity for social bonding. Within this bonding process, the amount of tone variations decreased, giving rise to the appearance of consonants. New articulations needed to be formed, and consequently grammatical rules for making sequences of utterances soon emerged. As language followed the path of logical argumentation, those melodic aspects of the primordial utterances evolved into music instead. Music thus developed from the sounds of passionate speech.

The Music Instinct

Why does music pervade our lives and those of all known human beings living today and in the recent past? Why do we feel compelled to engage in musical activity, or at least simply enjoy listening to music even if we choose not to actively participate? I argue that this is because musicality--communication using variations in pitch, rhythm, dynamics and timbre, by a combination of the voice, body (as in dance), and material culture--was essential to the lives of our pre-linguistic hominin ancestors. As a consequence we have inherited a desire to engage with music, even if this has no adaptive benefit for us today as a species whose communication system is dominated by spoken language. In this article I provide a summary of the arguments to support this view.

Effect of selective attention on the segregation of interleaved melodies.

The role of attention in streaming remains controversial and the data from the literature appear at first sight to be inconsistent [C. Alain and L. J. Bernstein, Curr. Opin. Otolarygol. Head Neck Surg. 16, 485–489 (2008)], aimed to reconcile these data arguing that selective attention may increase segregation via a sensory mechanism that enhances the processing of task‐relevant acoustic information, and a suppression mechanism that attenuates the processing of task‐irrelevant stimuli. To test this hypothesis, we proposed an interleaved melody paradigm with various rhythm conditions applied to familiar target melodies and unfamiliar masking melodies. All targets and maskers had the same pitch ranges and timbre variations. No rhythm cue was available in condition 1 (irregular target and masker rhythms). The masker was presented at a regular rhythm in condition 2, the target remaining irregular. Performance over chance in condition 1 indicated that attention enables listeners to extract a familiar melody fro...

Automated fingering services for woodwinds: development of a "virtual clarinet"

The Virtual Flute is a popular web service that recommends alternative fingerings for difficult passages, timbre variations, intonations or multiphonics. Its database was generated by a machine‐learned expert system analysing waveguide models for all 39,744 fingerings. The relatively simple geometry of the flute and its tone holes allowed a simple yet accurate model. The development of similar systems for other woodwinds faces greater modelling and computational challenges. For example, the clarinet has a more complex geometry, with tone holes whose radius and length vary by factors of 4.2 and 2.8. Further, it has several million different fingerings. To achieve the required accuracy, individual measurements of each hole separately and of mouthpiece and bell, as well as several dozen fingering examples, were used to determine parameters of a still simple waveguide model. The model uses conical and cylindrical segments with parallel and shunt impedances at junctions, representing tone holes. This approach of incrementally enhancing our waveguide model allows computational advantages: an efficient, woodwind‐generic software framework is built that can adapt to the instrument of interest. We report interim results with such a system, with further potential applications in the design of woodwind instruments and other acoustic duct systems.

Evaluating Vocal‐Tract Influence in the Production of Saxophone Multiphonics

A new approach for the analysis of vocal‐tract influence in single‐reed woodwind instruments during performance was recently reported (Scavone et. al., 2008). Two types of vocal‐tract influence were observed. When the downstream air column provides only weak support of a given note, players can use a strong and narrow‐bandwidth upstream resonance to override the reed vibrations, such as when pitch bending or playing extended register notes. Performers can also use a more wide‐bandwidth upstream resonance to affect subtle timbre variations when playing notes over the full range of the instrument. The research reported here addresses the performance of multiphonic tones, for which the results of the previously mentioned study were less conclusive. While it is clear that upstream influence is involved in the production of multiphonics, we are interested in determining whether performers must support a specific intermodulation component or a wider bandwidth range of components for proper production. The latest results of this research will be reported.

Exploration of timbre variations in music performance

Timbre has seen during the twentieth century a growing attention from both musicians and scientists, the former to expand a traditional music system until now governed by the structures of pitches, the latter to better understand how timbre is produced and how it is processed by the perceptive and cognitive systems. In the music performance context, many studies deal with the role of timing and dynamics, but much fewer are dedicated to the one of timbre. The works presented here aim at showing the importance of timbre variations from two points of view: the production of sounds and their perception. The relations between the control parameters (mouth pressure and reed aperture) of a simplified physics‐based clarinet synthesis model and the generated timbres have been investigated. Experiments have further been done to measure the within‐individual consistency of timbre variations of a clarinet player repeating several instances of a musical excerpt from a Bach piece while keeping the same musical intention. Brightness variations characterized by the time‐varying Spectral Centroid showed a strong consistency across the repetitions. The influence of such brightness variations on the perceived musical quality of a performance was then assessed thanks to an analysis‐transformation‐synthesis paradigm.

Measurement of vocal-tract influence during saxophone performance

This paper presents experimental results that quantify the range of influence of vocal tract manipulations used in saxophone performance. The experiments utilized a measurement system that provides a relative comparison of the upstream windway and downstream air column impedances under normal playing conditions, allowing researchers and players to investigate the effect of vocal-tract manipulations in real time. Playing experiments explored vocal-tract influence over the full range of the saxophone, as well as when performing special effects such as pitch bending, multiphonics, and "bugling." The results show that, under certain conditions, players can create an upstream windway resonance that is strong enough to override the downstream system in controlling reed vibrations. This can occur when the downstream air column provides only weak support of a given note or effect, especially for notes with fundamental frequencies an octave below the air column cutoff frequency and higher. Vocal-tract influence is clearly demonstrated when pitch bending notes high in the traditional range of the alto saxophone and when playing in the saxophone's extended register. Subtle timbre variations via tongue position changes are possible for most notes in the saxophone's traditional range and can affect spectral content from at least 800-2000 Hz.

La duración de la vocal simple y de las homólogas en el español venezolano: el caso de pares mínimos

En el habla la presencia de un núcleo vocálico indica la presencia de una sílaba. En consecuencia, dos vocales consecutivas implican la existencia de dos sílabas, estando el límite silábico entre las dos vocales. ¿Cuáles índices podemos utilizar para distinguir en español una vocal simple de dos vocales consecutivas idénticas como en el caso de Sara y Sahara? Para responder a esta pregunta, hemos estudiado un corpus constituido por 21 pares mínimos del tipo Sara/Sahara. El análisis acústico muestra que el índice que prevalece para discriminar una vocal simple de una doble es la duración vocálica segmental. Otros índices tales como la variación de altura, de timbre o amplitud, así como la presencia de una breve pausa se presentaron algunas veces pero no de manera sistemática. Se realizó un estudio perceptivo para determinar el papel de la duración vocálica utilizando estímulos para los cuales la duración de la vocal fue modificada alargando la duración original de la vocal simple. Los sujetos realizaron una tarea de decisión léxica indicando la palabra que escuchaban de dos que se les presentaba visualmente. Los resultados demuestran que la duración vocálica puede ser un índice suficiente para diferenciar una vocal simple de una vocal doble.

The Virtual Flute: an advanced fingering guide generated via machine intelligence

The Virtual Flute is a web service that provides many thousands of machine-predicted alternative fingerings. Alternative fingerings can offer variations in intonation and timbre, and can be easier to play in different musical contexts. Many play multiphonics. An advanced fingering guide is invaluable when exotic effects and demanding passages are required of the player. The Virtual Flute uses an expert system that predicts musical properties from acoustic impedance spectra. Impedance spectra for the 39,744 acoustic configurations of the flute are generated by a physical model of the instrument, some parameters of which are machine-learned. We report the construction and use of The Virtual Flute (http://www.phys.unsw.edu.au/music/flute/virtual/).

Influence of tonal context and timbral variation on perception of pitch.

In this study, spectral timbre's effect on pitch perception is examined in varying contexts. In two experiments, subjects detected pitch deviations of tones differing in brightness in an isolated context in which they compared two tones, in a tone-series context in which they judged whether the last tone of a simple sequence was in or out of tune, and in a melodic context in which they determined whether the last note of familiar melodies was in or out of tune. Timbre influenced pitch judgments in all the conditions, but increasing tonal context allowed the subjects to extract pitch information more accurately. This appears to be due to two factors: (1) The presence of extra tones creates a stronger reference point from which to judge pitch, and (2) the melodies' tonal structure gives more cues that facilitate pitch extraction, even in the face of conflicting spectral information.