MADLAB Electronic Kit - Bagpipes
The Bagpipe Kit is an audio oscillator kit similar to the MadLab Electronic Kit - Nerve Coil. The bagpipe can generate 8 different tones from 5 kHz (5000 cyl per second) to 300 Hz.
Move the pin across the network of resistors R1 to R8 that make up the keyboard. The voltage at the tip of the pen will change each time a resistor is touched and generate a tone.