Willi Apel (1893-1988)
A German-American musicologist, made a substantial
contribution to the understanding of early music through his many publications.
Among these are "The Notation of Polyphonic Music,
900-1600" and "Gregorian Chant" (1958).
Many generations of American music students have relied on "The
Harvard Dictionary of Music" and the two-volume "Historical
Anthology of Music". This latter publication was a collaboration
with Archibald T. Davison.