Chapter 6
General Summary

We began by asking what makes music so uniquely motive and emotionally compelling. In response, it was argued that music exhibits perceptual animacy cues, indications that it emanates from a living source. Because it would be useful for any animal to distinguish living things from nonliving things, it is reasonable to suppose that humans might have a special perceptual capacity to do so. Both animate and inanimate sound sources tend to evoke the experience of auditory streams. As musical analogs of auditory streams, musical lines may be necessary, though not necessarily sufficient, for the perception of musical animacy.

In addition to being perceived as animate, musical sounds might in fact be perceived as being distinctly human in origin and character. Three anthropomimetic properties of music might help to distinguish musical lines as animate rather than inanimate streams. By merit of being pitched sounds with a large degree of sonic harmonicity and appropriate pitch height, they strongly resemble vocally produced sounds. Because of their rhythmicity, they could preferentially activate perceptual systems dedicated to processing human movement. Finally, because musical lines exhibit organized acoustic patterns, they could suggest that an intelligent or linguistic creature might have produced them. By combining the essence of three prototypically human residues, music might act as a ‘supernormal stimulus’—one that hijacks our tendency to strongly respond to the sound of others of our own kind.

Empirical approaches were then used to investigate the influence of polyphonic voice multiplicity on musical emotion perception. Nominal voice multiplicity was distinguished from perceptual voice numerosity, which was itself investigated by employing a voice denumeration task. It was found that in polyphonic western compositions, one should expect textures with more polyphonic voices to sound less lonely, and to be associated with increased positive affect more generally. Some evidence was found that ‘personal emotions’ and ‘musical emotions’ could be somewhat distinct, at least in the context of experimental protocol. Further work would be needed to determine whether the multiplicity–positivity connection is indeed due to an implied social situation, or could be attributed to another cause, such as enjoyment of compositional complexity.

Finally, compositional organization according to musical line was found to mediate correspondences between melodic speed and pitch height. This relationship appears both when considering music part by part, as well as instrument by instrument. It would seem that composers treat musical lines as independent musical agents with different speeds and trajectories just as listeners are likely to perceive them as such. A complete account of the causal chain that has led to this practice might, however, be considerably complex and rely on as-yet uncollected experimental evidence from several sources.