Lite2Sound PX is nice for ambient sound exploration, but there’s no reason you can’t create modulated light specifically for the purpose of music. The downloadable PDF “Lite2Sound Tone Wheels vol. 1″ contains special circular patterns that you can print. Spin the patterns on a turntable or fan motor, and shine a laser pointer at it. The reflected light carries harmonic modulations for Lite2Sound to receive.
The patterns have multiple tracks arranged in harmonic relationships based on just intonation. So you also get a chance to hear pure harmonic intervals that are often out of reach with modern instruments.
Thanks to D. Holzer for his article A Brief History of Optical Synthesis which contributed to the inspiration to publish this work.
New for 2014: An updated version of the mini space rockers DIY electronic drum synth circuit. Mini Space Rockers Plus adds an LM386 audio amplifier for more power and volume from the speaker. The PDF document contains the MiniSR+ schematic, solderless breadboard layout, formulas for 25 sound variations, and reference photos of the circuit on my breadboard. Also, the transistors have been changed to 2N3904/2N3906 to make them easier to find. Have fun learning and rock out with Mini Space Rockers Plus!