Demonstrating an early version of Trombone-Propelled Electronics at Ursa Major. Note the Commodore 64 sitting on top of the Stargate chassis -- a few months later I stuffed the computer's motherboard inside the Ursa Major, and connected the keyboard, monitor and disc drive only when I need to program it. Speaker coupled to trombone mouthpiece sits behind me on the table. Shaft encoder on trombone crook is turned by a retractable keychain -- this was so noisy in my left ear that I replaced it a few weeks later with a retractable dog leash. Photo probably by Christopher Moore.