Learning how to program in Max for Live for the first time, I built a patch that allows me to play my iPad like a cello using the gyro motion control features found in Mira.
Rotating the iPad mimics the action of pulling a bow across the strings, and changing the direction of rotation starts a new note. You can change the volume and expression of each note in real time by pulling the iPad faster or slower. The Max patch sends CC channel data to Ableton Live, where the sound synthesis in controlled.
The best part is that you don't need any musical knowledge to perform with this virtual cello, because CelloPad chooses the notes for you. I built a small probability distribution curve in Max for Live to compose random melodies within predetermined chord progressions. All you have to do is tap the screen to advance to the next chord, and CelloPad writes the melody with every new note.
Thanks to the Max community forum members for an incredibly helpful archive of posts!