If there is a hip weird band in your town, it's highly probable that they either have a theremin or are saving up for one. The only instrument that you don't have to touch in order to play, the theremin is experiencing a bizarre surge in popularity, and all around the world, musicians are waving their arms in the air, making bizarre, if not exactly musical, sounds.
So of course you need one. You could buy a Moog Etherwave-indeed, it's a great machine. But PAiA, the venerable kit manufacturer, makes a terrific theremin kit for half the price and with twice the versatility: the Theremax. You can order a full kit, with board, electronic parts, silkscreened faceplate, antennas, and wooden lectern case, for under $200 shipped. If you have some other case you want to use, that's fine-the faceplate and case make up half the total price. The full kit, however, contains everything you'll need to make the complete theremin, right down to the hookup wire. PAiA kits are great for beginners, because they come with complete step-by-step instructions and a guide to soldering, and the Theremax is particularly easy to build; the board and case are very spacious, and you won't have to aim your trembling hot iron into a lot of tight corners.
Perhaps the best thing about the Theremax is that it has CV and gate outputs. This means that you can use it to control an old monosynth, or if you have a CV-to-MIDI converter, any synth. It also has a unique velocity control, which automatically adjusts the timbre according to how fast you move your hands, and a knob to fade between sine (traditional) and triangle waves. The basic Etherwave, excellent as it is, has none of this stuff. With practice, the Theremax can be extraordinarily expressive-the very things that make it temperamental also give it its personality. You'll find you may need to open up the case and recalibrate often, but since the lid is attached with velcro, this is a cinch.
For a full tutorial on how to build the PAiA Theremax and a brief history of the theremin, visit the "Bonus Articles" page at tapeop.com. ($169 direct for complete kit; www.paia.com)