James Tenney's composition Wake, for four tenor drums, is based on the following rhythm (which occurs in several of Charles Ives' pieces):
In Wake, this rhythm is performed first by single strokes on a single drum, then by two strokes (separated in time by the interval of a 32nd note), then three strokes, then four. Then another drum joins, also adding 32nd-note spaced repetitions. A third drum is then added, and finally a fourth; there is a short coda, and the piece ends.
I heard the piece performed by William Winant, Daniel Kennedy, David Rosenthal, and Kenneth Piascik at a concert of the San Francisco Contemporary Music Players, given March 17, 1997 at the Yerba Buena Center for the Arts Theatre. I was seated in the front row, and the drums were close to the front of the stage. The precision and intensity of the performance was wonderful! The predictability of the piece's progression contributed greatly to its hypnotic effect, but the level of sound is high enough to demand close and continuous attention throughout its 4'30" length.
Moments after the piece was over, the idea for this visualization came to mind:
In my visualization of Tenney's piece, this rhythm is shown as six lines (I think of them as "sticks") arranged radially, with one revolution of the circle corresponding to two measures in the piece; the starting point of the rhythm is the lowest stick (the "down" beat), and the rhythm proceeds clockwise from there:
What happens during the animation is that little circles of color ("drums") appear near the center of the circle, and follow a spiral path outward. When a drum strikes a stick, there's a little explosion (and an extending "trail") corresponding to the sound. The drums are added one at a time, closely spaced to create a visual "wake" that corresponds to the aural one.
At the end of the piece, the rhythm departs from the original pattern, and the sticks move to reflect that.
In 1998 I did a more polished version of Wake.