Click on the buttons and play music! You can also press A, S, D, F, G, H, J on your keyboard for a smoother experience. (recommended)
For my next iteration, there will be more than 7 buttons as is present. I plan on record all 12 notes to formulate major minor and 7th chords! The layout will be in a similar fashion to an Omnichord, but also including the keys (as displayed here) so you can see which notes are being played in that chord.