Timbre Phrases

2015 – Encoding and decoding spectrotemporal timbre features in expressive musical phrasing. A timbre analysis synthesis project to shape musical phrases with timbre for 2015 meeting of the Society for Music Perception and Cognition in Nashville, TN.

Multi-dimensional scaling models of timbre can explain our perception of timbre dissimilarities for single tones, but they hardly explain the range of discernible timbres a single instrument can produce, nor do they describe the role of timbre in musical performance. Hypothesizing that nuanced intra-instrumental timbre variations play a prominent role in shaping phrases, we designed an investigation of timbre in phrasing. We asked performers to interpret two streams of notes into three different phrase shapes. Recordings were obtained and analyzed for amplitude, timing, and spectro-temporal features contributing to phrase shape. A correlation between the spectro-temporal features and the phrase shape was found, suggesting that timbre variation predictably contributes to phrase shape. Specifically spectral centroid in mid-range frequencies (5-10 kHz) from the third to fifth notes in each stream showed a trajectory corresponding to the intended phrase shape. This work suggests that timbre trajectories over a stream of notes may contribute to listener perception of phrase shapes as do amplitude and timing trajectories.