This is a demo of Curtis (App Store link), a $1 granular synthesizer application for the iPhone.
Granular synthesis works by combining many tiny grains of sound from an existing recording, generally creating new sounds with the textural properties of the recording. Granular synthesis allows you to regenerate the recording, playing it forward or backward at any speed, to skip around the recording playing tiny slices of it at random, or to loop a small portion with a varying loop size.
1] Touch the screen with two fingers and rotate a quarter circle to activate recording mode.
2] Use your phone’s microphone to record any sound. Try your voice, music from the radio, an instrument, your dog, anything!
3] Touch the screen with two fingers again to stop recording.
4] Touch or drag one finger anywhere on the screen to control grain synthesis. The long axis of the phone controls your read position; use this to select the portion of the recording you wish to read from. The short axis of the phone controls the grain size; use this to sample tiny slices or bigger chunks.
5] Double tap to disable or enable position slew. With slew enabled, the read position slowly moves to where you tapped. With slew disabled, you can jump directly to new positions in the recording.
More info at TheStrangeAgency site.
If you’ve used Curtis, leave a comment with your thoughts!