Polyphony is a musical texture consisting of several independent melodic voices, as opposed to music with just one voice (monophony) or music with one dominant melodic voice accompanied by chords (homophony).
The term is usually used in reference to music of the late Middle Ages and Renaissance: Baroque forms such as the fugue which might be called polyphonic are usually described instead as contrapuntal. Also, as opposed to the species terminology of counterpoint, polyphony was generally either "pitch-against-pitch"/"point-against-point" or "sustained-pitch" in one part with melismas of varying lengths in another (van der Werf, 1997). In all cases the conception was likely what Margaret Bent (1999) calls "dyadic counterpoint", with each part being written generally against one other part, with all parts modified if needed in the end. This point-against-point conception is opposed to "successive composition", where voices were written in an order with each new voice fitting into the whole so far constructed, which was previously assumed.
In a contemporary usage which applies specifically to electronic musical instruments, the word can mean the simultaneous sounding of more than one note; hence, a polyphonic synthesiser is one capable of playing more than one note at a time. Such an instrument capable of playing, say, 16 notes at once is said to have 16 voice polyphony.
Two treatises, both dating from c. 900, are usually considered the oldest surviving part-music though they are note-against-note, voices move mostly in parallel octaves, fifths, and fourths, and they were not intended to be performed. The 'Winchester Tropers ', from c. 1000, are the oldest surviving example of practical rather than pedagogical polyphony, though intervals, pitch levels, and durations are often not indicated. (van der Werf, 1997)
- Hendrik van der Werf (1997). "Early Western polyphony", Companion to Medieval & Renaissance Music. Oxford University Press. ISBN 0198165404.
- Margaret Bent (1999). "The Grammar of Early Music: Preconditions for Analysis", Tonal Structures of Early Music. New York: Garland Publishing. ISBN 0815323883.
- Albright, Daniel (2004). Modernism and Music: An Anthology of Sources. University of Chicago Press. ISBN 0226012670.
- Thirteenth-Century Polyphony