The Rhythmicon

The Rhythmicon was a musical keyboard instrument built in 1931 by Leon Theremin at the request of composer/theorist Henry Cowell. Each key of the Rhythmicon played a repeated tone, proportional in pitch and rhythm to the overtone series (the second key played twice as high and twice as fast as the first key. The third key played three times higher and repeated three times faster then the first key, etc.)

"My favorite is the rhythmicon. Because that instrument, from its very conception, was intellectual in nature, and I find that the online version really does work well on several levels. As a learning or pedagogical tool, or musical understanding stretcher, it seems genuinely useful to me. And as a compositional medium it's got both simplicity and depth, and either way the results that come out are appealing."

—Bart Hopkin, Experimental Musical Instruments

The Stand-alone Rhythmicon Download

You may download the stand-alone Rhythmicon application and run it on your computer.
You will need a JMSL license, and can get a free 30 day demo license here.
You can purchase a license here

The Online Rhythmicon

Here we present a virtual Rhythmicon that you can perform in your web browser (takes a fair amount of fiddling these days to get your web browser to allow Java Applets to run, so we encourage you to download the stand-alone app above). You can play the Rhythmicon by selecting whether you want to play the Lite or Full-featured version. (If you have a slower computer, or are experiencing a high CPU load, we suggest you play the low-fidelity version of the Rhythmicon.) To learn how to use the Rhythmicon, our helpful Rhythmicon guide is a good place to start.

Play Rhythmicon Lite Play Full-featured Rhythmicon
  • Multiple Rhythmicons
  • Control over tempo and fundamental frequency of each Rhythmicon
  • Control of each key's attack, release, sustain, and accent contour
  • Interactive Play hi-fidelity version (CD quality audio, for faster computers)
    Interactive Play low-fidelity version (22050 fps, for slower computers)

The Rhythmicon was designed and programmed in Java Music Specification Language and JSyn by Nick Didkovsky, and commissioned by American Public Media. Nick would like to thank Preston Wright for the invitation to work on this project, and Phil Burk for the many insightful discussions, supporting software, and of course, JSyn. Nick would also like to thank the following beta testers who helped with bug reports and creative suggestions: David Birchfield, Philip Blackburn, Phil Burk, James Forrest, Kevin Norton, Chris Pepper, Larry Polansky, John Roulat, and Peter Selmayr.