The creators at ZooZ Mobile describe ZooZBeat as a “gesture-based mobile music studio,” and in their demos they did indeed control tonality and volume by varying the intensity and direction of a waving or shaking motion.
But if you want more fine-tuned control, an on-screen editor (shown in the screenshot) lets you use your fingertip to make changes.
ZooZBeat is available in either a “Lite” version ($1 for the Apple folks, free for the Nokias) or a full version ($3 all platforms, found at the link here) with support for voice recording, the ability to play with others, and more beat and instrument options.
Note: This link takes you to the vendor’s site. From there, you can follow the link to the iTunes App Store, where you can download the latest version of the software.
–Yardena Arar