Rotifer - specification

Rotifer - A Polyrhythm Teaching Toy

Rotifer is my working name for a gadget I've been thinking about for a long time, currently developing a prototype for testing.


I've been a fan of rhythm in general, and non-Western polyrhythm in particular, for many years. At workshops such as Ta Ke Ti Na, I frequently visualize the rhythms as interlocking wheels or gears, like the Spirograph toy I played with as a child. The experience is often strong enough to be called a hallucination.

As far as I know, there is no single accepted notation for rhythm, and I've rarely seen a representation that spaced rhythmic components around circles, instead of along lines. (The only example I know is from Reinhard Flatischler's book _The Forgotten Power of Rhythm_ cf. page 73, "Joint Cycles.") Rotifer is my attempt to make this concept available to others, while I experiment with it for myself.


The Rotifer prototype should be a Web-accessible gadget that demonstrates polyrhythms. It will combine an animated visual display of the rhythm with several sound clips, that play in synchrony with the display.

Version 1: Display a blank circle with a "hand" that sweeps around, (like the second hand of a watch, but faster), say about once per second. Around the rim of the circle are two concentric bands, each with several "pips" equally spaced around its circumference (they can be dots, or squares, or something). The two bands have a different number of pips (say, two in the inner band, three in the outer band), and as the hand sweeps around, each pip plays a sound as the hand passes it. The pips in one band all play the same sound, and the pips in the other band play a different sound. (I'd like a third sound for when the pips in both bands coincide, but I can let this go if necessary.) The sounds are very short, like drum hits or hand claps. It's okay if the graphics are kind of simple and crude, but it's important that the visual display and the sounds be synchronized fairly closely to get the effect I want.

Version 2: Same, plus several controls to select (a) the tempo (the speed at which the hand sweeps around), (b) number of pips in inner band, (c) number of pips in outer band. The controls can be drop-down boxes, or sliders, or what have you.

Version 3: Same, plus the capability to adjust the pip locations manually, by widget controls (simple but clumsy) or by dragging with the cursor (intuitive but complicated). Now, each band has several parameters: (i) the number of equally spaced "quanta" which are the divisions where pips can reside, (ii) the number of pips, which may be variable, (iii) the location of each pip. (All pips in a given band still play the same sound, though.)

This may be a much more difficult task, and I won't be surprised if it turns out to be impractical, but I'm putting out the idea anyway. It seems to me that this will require a new widget, essentially a circular slider, but perhaps there are other ways to implement it. I'll be quite happy with Version 2, if 3 turns out to be too difficult.

Version 4: Same, plus controls to select the number of bands, and to select the sound for each band. This version should include a way to save and load configurations in files, too, because now it becomes a full-blown notation for just about any rhythm.

Some links

This page maintained by Wil Howitt
Last updated 23 April 2002