Available from the BBC's Science Playground site is a downloadable gem that is sure to be the hit of your office or dormitory. The Desktop Theremin (Mac/Win; www.bbc.co.uk/science/playground/theremin1.shtml) is a standalone, Shockwave-driven re-creation of that classic instrument with a cleverly designed graphical user interface.

The “instrument” resembles a portable television with a single antenna displaying Professor Theremin fronting an orchestra. To play the virtual theremin, simply click on the on/off switch and move your mouse. You can place the computer's cursor anywhere on your screen. Moving the cursor to the right raises the theremin's pitch, and moving the cursor to the left lowers the pitch. Move the cursor to the up and down to increase or decrease the volume, respectively. As you play, you will also notice that Professor Theremin is playing with you, though his hand movements are contrary to what would happen if you played a real theremin (for example, you move your hand toward the pitch antenna to play higher pitches).

However, the fun has just begun! The six buttons below the television screen let you add looped material — beats, pads, and breaks — behind your theremin playing. The Weirdness control changes the theremin's timbre from clean to buzzy. Tempo increment and decrement buttons, which raise and lower the pitch of the accompaniment along with the tempo, are also available. To top it off, a simulated oscilloscope shows you the wavelength of the pitches you're playing. If you have never played a real theremin, don't worry. The application plays discreet pitches, so even a rank beginner can play in tune like a pro.