What are they?

Each rhythm in the polyrhythm gets a pitch depending on the number of beats in the measure. The result is harmonious for normal polyrhythms, as the pitches are all in the harmonic series.

This idea was originally explored by Theremin with his mechanical Harmonic Rhythmicon. It's based on ideas and work by the composers Charles Seeger and Henry Cowell.

Click the link after the video to find out more about each type of harmonic polyrhythm and watch more videos. You can play any of these rhythms endlessly with the software Bounce Metronome Pro. See the page about its Harmonic Polyrhythms Feature for details.

With the more exotic 4/4 : 4/3 type polyrhythms, the measure beats also vary in size, and so in pitch. Then you get the likes of the golden ratio rhythm, with no exact number of beats to the measure. When that happens, the pitches are no longer in the harmonic series and you can get "inharmonic" pitches.

Note: In some of these clips the notes are all dropped down into the same octave, to reduce the pitch range.

More pages to follow for some of the other types of harmonic polyrhythm:

You can explore other ways of giving pitches to polyrhythms such as the subharmonic series, or just choose a pitch for each rhythm.

Also you get the harmonic polyrhythmic buzz rolls and other polyrhythmic drum rudiments and rhythms with varying note sizes.

Use these videos as a resource

You can use any of these videos as a resource for your own website or wikis, or make more of them yourself - see Add videos like these to your own site

Play these rhythms and animations at any tempo with Bounce Metronome

You can use Bounce Metronome Pro to practise these and many more rhythms at any tempo, including changing tempo. See Harmonic Polyrhythms in the Features list.