This project by Collin uses a familiar schematic โ€” the light-sensitive oscillator (aka โ€œphotothereminโ€) as originally described in Forrest Mimsโ€™ book Timer, Op Amp and Optoelectronic Circuits & Projects. Once he got the hang of securing each part in place for soldering, the rest of the process was more or less straightforward, and the circuit worked the first time he tested it.