The document describes creating a fourth sound using the Rhythmus instrument. The creator adjusted the four sliders on the instrument until satisfied with the sound, then experimented with adding and removing the buttons below to further refine the sound until pleased with the result.

1. For my fourth sound I used the Rhythmus instrument to create
a small musical piece. I started by adjusting the four sliders until
I was happy about the sound and then I decided to try adding
and removing the buttons below until I was happy with it