iThereal

iThereal is a multi-touch trackpad-controlled virtual Theremin. iThereal can be used to create music with a classic Theremin sound while staying true to a Theremin feel.
A Theremin often has a loop antenna on the left that manipulates the volume and an upright antenna on the right which controls the pitch of a note.

The proximity of the musician's hands affect the quality of the sound the Theremin emits. iThereal mimics these controls with touches on a trackpad.