Back in 2007 I wrote an application called SpaceTheremin. It is a simple app that lets you use your mouse to control a virtual theremin by moving it over a beautiful public domain image from the Hubble Telescope to control pitch and volume.
Over the years I also released versions for Linux, webOS, and OSX (via the Apple Store). It’s been downloaded tens of thousands of times and is a fun noise toy.
It’s available on the Zeta Centauri website if you’d like to check it out.