Music Perception, Vol. 10, No. 4 (1993) pp. 435-444.
Experimental evidence has shown that the perceptual segregation of concurrent auditory streams is enhanced when tone onsets are asynchronous rather than synchronous. Previous research has shown that the amount of onset synchrony is significantly less for polyphonic works than for homophonic works. In this study, an analysis of 15 polyphonic works by J. S. Bach shows that the amount of onset synchrony is significantly less than would be expected by chance, and so suggests that the synchronous onsets are intentionally minimized by the composer. The results are consistent with the objective of maintaining the perceptual independence of the polyphonic voices.