Polyrhythm

Polyrhythm is the simultaneous sounding of two or more independent rhythms. A simple example of a polyrhythm is 3 evenly-spaced notes against 2, with the 3-beat pattern being faster than the 2-beat pattern, so that they both take the same amount of time. Other simple polyrhythms are 3:4, 4:3, 5:4, 7:4, etc. Another form of polyrhythm, which might also be termed polymeter, would be phrasing to suggest a different meter than the one being played by the rest of the ensemble. A common example of this in jazz would be phrasing quarter notes in groupings of 3 to suggest 3/4 time while the ensemble plays in 4/4. Compare with hemiola (not a polyrhythm). Traditional African music is heavily polyrhythmic, although, unlike below, the downbeats do not usually coincide. Frank Zappa, especially towards the end of his career, experimented a lot with complex polyrhythms, such as 11:17, and even nested polyrhythms. The metal band Meshuggah also have some polyrhythms in their music, although their quirkiness is mostly of a polymetric nature. The band Tool also incorporates polyrhythms in their music. Much minimalist and totalist music makes extensive use of polyrhythms. Henry Cowell and Conlon Nancarrow created music with yet more complex polytempo and using irrational numbers like pi:e.

External links

• Tempo Mental- Article by Steve Vai on Polyrhythms
• Drums Database- More Polyrhythms
• polyPulse An athenaCL netTool for on-line, web-based MIDI polyrhythm generation