The BCKit-1 is a simple project for building a two transistor ribbon controller as outlined here on the PAiA website:

http://www.paia.com/bckit1/

In the pdf linked below are details for a variation to the build with a 3v solar cell as the power source with a controller strip made from a piece of anti-static conductive plastic. The cell works as a light sensor so covering it with your hand works to vary the voltage and the frequency of the sound produced--the probe can be used to set an initial frequency and the light to the cell, the variation, or vice versa.

http://paia.com/manuals/docs/PTph/bck1/ ... _Build.pdf

This Radio Shack / Make project is along the same lines and possibly a way to use your BCKit-1:

http://www.radioshack.com/graphics/uc/r ... Pencil.pdf