Theremin

Transforms your graphic tablet into an instrument

This program lets you control the frequency, pan, amplitude and modulation of a sine wave by gesture. But it also lets you replace the sine wave by any wave file...

The orange area corresponds to the graphic tablet. The position of the stylus on the tablet is represented by a cross. A line is drawn to show the orientation of the stylus, as well as a plain circle, which corresponds to the pressure.
The position of the stylus determines the frequency (Y coordinate) and the pan (X coordinate) of the audio signal generated. The pressure corresponds to the amplitude, and the tilt to the amount of frequency modulation.
In addition to the default mode in which Theremin lets you play a sine wave, you can select any .wav file to use your own sample data. It can be a full guitar or drum loop, or a single cycle of an analog waveform for example. In both modes, a delay effect can be inserted before the audio output.