Build a theremin!

Introduction

The theremin is one of the first electric instruments, invented in the 1930s. Despite its relative simplicity, its unique sound can be hauntingly beautiful, deeply elegant, or just downright cool. The two "antennas" are "plates" in a capacitor, with the other "plates" being the thereminist's hands - by moving his hands, he adjusts the capacitance and controls the volume and pitch of the oscillation produced. This project aims to build a theremin using stock circuit components.

Background Reading

This seems to be a fairly straightforward analog electronics project. There's a Wikipedia explanation of the operating principles, and a Wikihow article (of course).