Another new music app today appeared on the App Store. FMScreen is described as:
FMScreen turns the iPhone into a musical instrument: an FM Synthesizer. Play, improvise, compose. Imagine the Theremin’s younger relative, only it fits in your pocket. Tap and slide your fingers on the iPod Touch/iPhone’s screen to generate sounds, control their frequency, duration, timber and amplitude.
An FM Synthesizer generates simple waveforms that interact to create complex sounds of varying timbre. The interaction with the screen of the iPhone allows controlling the frequency of a sine wave (carrier), and the the amount of modulation (richness of the sound). The amplitude/volume of the sound is controlled by the inclination of the iPhone /iPod itself.
I’ve only had a very short time to play with this, so I’ll post something more detailed when I get more time.