This is a beautiful thing.
A tangible rhythm sequencer. Ball bearings are used to trigger drum sounds. Visual feedback is displayed from underneath to indicate the current time and the state of each ball bearing.
Update: I just noticed this “bubble gum sequencer” video, same idea, but the video explains the process much better.
The Bubblegum Sequencer is a physical step sequencer that lets you create drumloops by arranging colored balls on a tangible surface. It generates MIDI events and can be used as an input device to control audio hardware and software. Finally, people can’t claim anymore that electronic music isn’t handmade.