William P. Mahrt, PhD, is a professor in the Department of Music at Stanford University, where he teaches Medieval and Renaissance music and directs the Stanford Early Music Singers. His scholarship deals with the relation of music and liturgy and music and poetry, as well as the music of Brahms. Dr. Mahrt was a founding member of the St. Ann Choir in 1963, and has been its director most years since 1964. He frequently leads workshops in the singing of Gregorian chant and the sacred music of the Renaissance and has lead many tours on music and liturgy to English cathedrals.