Two studies are reported related to musical instrument timbre qualia. In the first study, open-ended interviews were conducted with 23 musicians who were asked to describe their phenomenal experiences of imagined sounds for 20 Western instruments. A content analysis of the transcribed interviews suggests 77 qualitative categories underlying the musicians’ descriptions. In a second study, 460 musician participants rated subsets of the same 20 imagined instrument sounds according to the 77 categories derived from Study 1. Principal component analyses were applied to the results of Study 2, yielding several models. Researcher interpretations of the components in these models were combined with the results of supplementary polls where musicians rated the descriptive utility of each candidate component, producing a final 20-dimensional timbre qualia model. The model dimensions include rumbling/low, soft/singing, watery/fluid, direct/loud, nasal/reedy, shrill/noisy, percussive, pure/clear, brassy/metallic, raspy/grainy, ringing/long decay, sparkling/brilliant, airy/breathy, resonant/vibrant, hollow, woody, muted/veiled, sustained/even, open, and focused/compact.

While absolute pitch (AP)-the ability to name musical pitches globally and without reference-is rare in expert musicians, anecdotal evidence suggests that some musicians may better identify pitches played on their primary instrument than pitches played on other instruments. We call this phenomenon "instrument-specific absolute pitch" (ISAP). In this paper we present a theory of ISAP. Specifically, we offer the hypothesis that some expert musicians without global AP may be able to more accurately identify pitches played on their primary instrument(s), and we propose timbral cues and articulatory motor imagery as two underlying mechanisms. Depending on whether informative timbral cues arise from performer-or instrument-specific idiosyncrasies or from timbre-facilitated tonotopic representations, we predict that performance may be enhanced for notes played by oneself, notes played on one's own personal instrument, and/or notes played on any exemplar of one's own instrument type. Sounds of one's primary instrument may moreover activate kinesthetic memory and motor imagery, aiding pitch identification. In order to demonstrate how our theory can be tested, we report the methodology and analysis of two exemplary experiments conducted on two case-study participants who are professional oboists. The aim of the first experiment was to determine whether the oboists demonstrated ISAP ability, while the purpose of the second experiment was to provide a preliminary investigation of the underlying mechanisms. The results of the first experiment revealed that only one of the two oboists showed an advantage for identifying oboe tones over piano tones. For this oboist demonstrating ISAP, the second experiment demonstrated that pitchnaming accuracy decreased and variance around the correct pitch value increased as an effect of transposition and motor interference, but not of instrument or performer. These preliminary data suggest that some musicians possess ISAP while others do not. Timbral cues and motor imagery may both play roles in the acquisition of this ability. Based on our case study findings, we provide methodological considerations and recommendations for future empirical testing of our theory of ISAP.

This paper offers a series of characterizations of prototypical musical timbres, called Timbre Trait Profiles, for 34 musical instruments common in Western orchestras and wind ensembles. These profiles represent the results of a study in which 243 musician participants imagined the sounds of various instruments and used the 20-dimensional model of musical instrument timbre qualia proposed by Reymore and Huron (2020) to rate their auditory image of each instrument. The rating means are visualized through radar plots, which provide timbral-linguistic thumbprints, and are summarized through snapshot profiles, which catalog the six highest- and three lowest-rated descriptors. The Euclidean distances among instruments offer a quantitative operationalization of semantic distances; these distances are illustrated through hierarchical clustering and multidimensional scaling. Exploratory Factor Analysis is used to analyze the latent structure of the rating data. Finally, results are used to assess Reymore and Huron’s 20-dimensional timbre qualia model, suggesting that the model is highly reliable. It is anticipated that the Timbre Trait Profiles can be applied in future perceptual/cognitive research on timbre and orchestration, in music theoretical analysis for both close readings and corpus studies, and in orchestration pedagogy.