Clapping Music visualization

A graphic system that displays the patterns in this systematic piece of music by Steve Reich.

A geometric grid of black circles and semicircles

Each horizontal row represents one rhythmic pattern, read from left to right. The top half of a circle represents one performer clapping; the bottom half represents the other performer.

Both performers clap the same rhythm throughout. They start out in sync: in the top row, the top halves and bottom halves of the circles are aligned. That pattern is repeated a number of times. Then one performer shifts a beat out of sync: on the second row, the bottoms of the circles are moved one beat to the left. That new pattern is repeated a number of times. Then on the third row, they shift another beat out of sync, and so on, until they end up back in sync at the end.

The performer who shifts in each row can be seen as diagonal stripes:

The performer who does not shift can be seen as vertical stripes:

Together these stripes create a pattern that reminds me of a surface of water with overlapping ripples in different directions.