The notation of polyphonic music, 900-1600

4th ed., rev. with commentary.

by Apel, Willi, 1893-1988.
Published: Mediaeval Academy of America, 1953

Gregorian chant

by Apel, Willi, 1893-1988.
Published: Indiana University Press, 1958

Masters of the keyboard; a brief survey of pianoforte music

by Apel, Willi, 1893-1988.
Published: Harvard Univ. Press, 1947

Harvard dictionary of music

2d ed., rev. and enl.

by Apel, Willi, 1893-1988.
Published: Belknap Press of Harvard University Press, 1969

The Harvard brief dictionary of music

by Apel, Willi, 1893-1988.
Published: Harvard University Press, 1960

The history of keyboard music to 1700

by Apel, Willi, 1893-1988.
Published: Indiana University Press, 1972

Historical anthology of music

Rev. ed.

by Davison, Archibald T. 1883-1961.
Published: Harvard University Press, 1949

The New Harvard dictionary of music

Published: Belknap Press of Harvard University Press, 1986

Early and late 15th century music

Published: Pleiades Records, 1974