Four experiments were conducted to explore the timbres of natural, continuant orchestral instruments with emulation based on sampling, frequency modulation ( FM) synthesis, and a hybrid consisting of sampling and synthesis techniques combined. Identification of instruments using verbal labels was significantly better for the natural and sampling- based signals than for either FM synthesis or the hybrid technique, a result also found for aural categorization. Perceptual scaling of timbral similarities demonstrated great consistency across a series of independent variables, including musical training, monophonic and stereo presentation, and long versus short signal durations. The first dimension of the classical multidimensional scaling (CMDS) solutions mapped onto long- time- average spectral centroid. The second dimension mapped onto a measure of spectral variability. Little evidence was found for the mapping of attack time or signal duration onto either dimension. A third dimension separated most natural instruments from their emulated counterparts. Experiments using verbal attribute ratings confirmed the correlation of spectral centroid, the first dimension of the perceptual space, and ratings of nasality; the second dimension correlated with spectral variability and modestly correlated with ratings of rich, brilliant, and tremulous. Mismatches of spectral distribution and variability resulted in poor emulations of the natural instruments. Results suggest that further study of centroid and time-variant psychophysical properties is warranted.

A study on the verbal attributes of timbre was conducted in an effort to interpret the dimensional configuration of the similarity spaces of simultaneously sounding wind instrument timbres. In the first experiment, subjects rated 10 wind instrument dyads on eight factorially pure semantic differentials from von Bismarck's (1974a) experiments. Results showed that the semantic differentials failed to differentiate among the 10 timbres. The semantic differential methodology was changed to verbal attribute magnitude estimation (VAME), in which a timbre is assigned an amount of a given attribute. This procedure resulted in better differentiation among the 10 timbres, the first factor including attributes such as heavy, hard, and loud, the second factor involving sharp and complex, a contrast with von Bismarck's results. Results of the VAME analysis separated alto saxophone dyads from all others, but mapped only moderately well onto the perceptual similarity spaces. It was suggested that many of the von Bismarck adjectives lacked ecological validity.

Experiments were conducted to explore the relationship between wind instrument dyad timbres and verbal attributes drawn from the musicological literature in order to compare and contrast results with studies using artificial stimuli and amusical rating scales. In the first experiment, all adjectives in Piston's (1955) "Orchestration" were collated and subsequently reduced to 61 examples. A checklist procedure was used in response to the dyad timbres to further reduce the set of adjectives to 21. The 21 adjectives were used in verbal attribute magnitude estimation of the 10 wind instrument dyad timbres. Principal components analysis of ratings revealed four verbal attribute factors, accounting for 90.604% of the variance: power, strident, plangent, and reed. Correlational analyses demonstrated an improvement in mapping between the ratings and perceptual similarity spaces over the procedure used in Part I of this study. The two-dimensional timbral circumplex was interpreted as having a principal dimension of nasality versus richness and a secondary dimension of reediness versus brilliance.

Timbral similarities among wind instrument duos were studied. Flute, oboe, E♭ alto saxophone, B♭ clarinet, and B♭ trumpet instrumentalists performed in all possible duo pairings (dyads). Source material included B♭4 unisons, unison melody, major thirds, and harmonized melody. Nonunison combinations had each instrument of the pair as the soprano, creating a total of six contexts. Music major and nonmusic major subjects rated the similarity of all possible pairs of dyads in each of the six contexts. Classical multidimensional scaling (MDS) was performed; contexts were treated as " subjects" in an individual differences scaling (INDSCAL) analysis of composite data. The resulting spaces had two stable, interpretable dimensions. From verbal attribute rating experiments ( Kendall & Carterette, in preparation, a), these were identified as " nasal" vs. " not nasal," and " rich" vs. " brilliant." A third dimension was interpreted as "simple" vs. "complex."Extrema in the space were associated with three of the five instruments: Trumpet (brilliant), saxophone (rich), and oboe ( nasal). Data that were amalgamated over contexts and plotted in two dimensions yielded a circumplicial configuration. Implications for orchestration are discussed and a theoretical model of timbre combinations and groupings is presented.

This study focuses on the performer-listener link of the chain of musical communication. Using different perceptual methods (categorization, matching, and rating), as well as acoustical analyses of timing and amplitude, we found that both musicians and nonmusicians could discern among the levels of expressive intent of violin, trumpet, clarinet, oboe, and piano performers. Time-contour profiles showed distinct signatures between instruments and across expressive levels, which affords a basis for perceptual discrimination. For example, for "appropriate" expressive performances, a gradual lengthening of successive durations leads to the cadence. Although synthesized versions based on performance timings led to less response accuracy than did the complete natural performance, evidence suggests that timing may be more salient as a perceptual cue than amplitude. We outline a metabolic communication theory of musical expression that is based on a system of sequences of states, and changes of state, which fill gaps of inexorable time. We assume that musical states have a flexible, topologically deformable nature. Our conception allows for hierarchies and structure in active music processing that static generative grammars do not. This theory is supported by the data, in which patterns of timings and amplitudes differed among and between instruments and levels of expression.

The basso continuo principle, as embodied in Rameau's theory of functional harmony, was paralleled by the introduction of drone instruments in the classical music of India. In order to understand how these two systems are tied together in human music perception, we studied the role of tambūrā interactions with North Indian rags played on the sitār. Raman (1914-1922) had applied his theory of discontinuous wave motion to mechanical and musical properties of the strings of the violin. He noted the remarkable, powerful harmonic series that arose from the nonlinear interaction of the tambürã string and grazing contact with its curved bridge. We analyzed the waveforms of the most common drone tunings. Each of the four strings was played with and without juari ("life-giving" threads). The upward transfer and spread of energy into higher partials imparts richness to tambūrā tones and underlies the use of different drone tunings for different rags. Specific notes of rāg scales are selectively and dynamically enhanced by different drone tunings. Based on coincident features of spectral and musical scale degrees, we computed an index of spectral complexity of the interactions of tambūrā tunings with rãg scales. We speculate that the use of juari contributes to stable pitch centers, implied scale modulation, and an improvisational flexibility.

It would seem anomalous that an orchestral musician would have less than normal hearing in order to monitor an exacting musical output. However, some recent studies show that a proportion of symphony musicians do have hearing impairments of various pathologies of which noise exposure, including the music alone, is the dominant causal factor. Intense music exposures in symphony orchestras often exceed the intensity standards of hearing conversation. A basic procedure for industrial hearing conservation is the control of the sound at the source, but the very purpose of the orchestra prevents its use. Hearing protection which is used voluntarily by some musicians presents a different sound picture. The control of intensity of music exposures is necessary but is separate from the concern of the present study with industrial issues and the perceptual-motor performance of musicians. Relevant aspects which are briefly reviewed include the incidence, susceptibility, and severity of hearing impairment among musicians; musical performance of the hearing impaired and the effects of various pathologies on their performance; medical-legal rules of impairment, disability, and handicap; and the incidence of compensible losses among musicians of certain orchestras. Illustrative results are presented of a preliminary study of hearing among 13 volunteer members of The Los Angeles Philharmonic Orchestra. It is suggested that a three- phase study be done: (1) a comparative study of hearing among symphony orchestras; (2) development of comprehensive tests to determine hearing-related performance; (3) provision of a rational basis for hearing criteria in the case of musicians for dealing with their employment, transfer, retirement, disability, handicap, and award of compensation. A fourth issue requiring concurrent study is the conserving of the hearing of orchestral musicians.

In studying the abstraction of musical ideas from diverse invariants, six-note melodies of varying note durations and note intensities were used as prototypes. Four types of transformations on a prototype distorted each of four musical components: contour, interval, loudness, and duration. In an acquisition phase, listeners heard simple transformations on a single prototype, but in recognition heard both simple and compound transformations as well as the prototype, which had been unheard in acquisition. Predictions were borne out, namely, that both prototypes and simple transformations were falsely recognized with greater certainty than any other transformed melodies; and latencies of recognition of the prototypes, an alternative measure of certainty, were shorter than latencies of recognition of any other transformed melodies. It is argued that the methods used enable the examination of the properties of musical transformation spaces.

In an experiment aimed at assessing dimensional properties of musical space, musicians rated the similarity of pairs of brief melodies on a 9-point scale. From our review of previous work, we hypothesized (1) that pitch variables would be considered more important than time or rhythmic variables by our subjects and (2) that the metrical consonance of pitch and duration patterns would generate a factor related to pattern regularity in listeners' musical space. Four melodies and their inversions were played in each of four rhythmic patterns (anapestic, dactylic, iambic, and trochaic) for a total of 1024 pattern pairs. Both multidimensional scaling and cluster analyses of similarity showed that at least five dimensions were needed for a good accounting of the perceptual space of these melodies. Surprisingly, the major dimensions found were rhythmic: (1) duple or triple rhythm, (2) accent first or last, and (3) iambic-dactylic versus trochaic-anapestic. Other dimensions were (4) rising or falling pitch and (5) the number of pitch—contour inflections. The tendency to rate patterns on the basis of time or rhythm (Dimensions I, II, and III) was negatively correlated with the tendency to rate patterns on the basis of pitch (Dimensions IV and V). It could not be determined whether this result depends on cognitive processing limitations, attention, or preferences. No factor was found that related to pattern regularity as we defined it.