The TunePitcher Kit is a DIY kit you need to assemble yourself. The ‘brain’ of the kit is a Teensy 3.1.

By connecting your Midi Keyboard with the Midi In, chords you play with odd octaves will get transposed by pressing one key on the even octaves. Keep it simple and play only C chords (major, minor, maj7 etc.) with your right hand. You easily can play around with various progressions. You want to do adjustments or create your own interface, hack the TunePitcher!