Real name: William A. Sethares

William A. "Bill" Sethares (b. 19 Apr 1955, Massachusetts) is an American music theorist and professor of electrical & computer engineering at the University of Wisconsin-Madison. Sethares is best known for his contributions to the "Dynamic Tonality" theory and groundbreaking work on formalizing musical consonance. He received a bachelor's degree from Brandeis University in 1978 and earned a Ph.D. from Cornell University in 1987.

In the 1990s, Bill Sethares began analyzing the research of R. Plomp and Willem J. M. Levelt, who first suggested in the mid-60s that consonance could be generalized beyond the harmonic series. Subsequently, he formalized the relationships between a tuning's notes and a timbre's partials that control "sensory consonance." His findings appeared in two articles, the '92 Relating Tuning and Timbre in Experimental Musical Instruments magazine and the '93 Local consonance and the relationship between timbre and scale published in the Journal of the Acoustical Society of America. William released two albums, Xenotonality and Exomusicology, exploring the practical application of his formalizations in music.