Fig. 1: The iPhone Bowls application synthesizes bell tones when you stir the main image with a finger, but the smaller images trigger sounds too.

The multitouch interface of the Apple iPhone and iPod touch offers lots of unexpected potential for musical control. Darwin Grosse of Cycling '74 noticed that secondary images in the Bowls Tibetan bell app ($1.99) also trigger sounds. “The sound is great — and appropriately haunting,” he reports. “That plus a [Korg] Kaoss Pad is a gig, man.” Swiping your finger sideways under the main image switches among instruments; do that fast enough and you can play arpeggios, as the Jordan Rudess MP3 on Oceanhouse's site demonstrates.

Keep the Effects window open in Bebot ($1.99) and you can get Kaossilator-style phrase looping, as well. Simply crank the Echo Repeat slider to maximum and back with your right thumb while playing notes with your left hand. In SurfaceDJ ($1.99), double-clicking a loop will mute it. — David Battino