Show HN: A beat composer by placing beans on paper [video]
https://www.youtube.com/watch?v=B9WNFpBFMP8Bean beat sequencer allows you to make music by placing beans on a piece of paper. The bean placement is captured by a webcam and Processing and Sonic-Pi together render the audio.
8 rows represent 8 instruments. 16 columns represent time slot. If a bean is placed in the time slot, the corresponding instrument for that row is played.