Adding a resistor between two circuit board points introduces controlled cross-connections that can produce musically useful malfunctions

Reed Ghazala’s circuit-bending method involves probing a circuit board by touching a resistor (start with around 1k ohm) between pairs of points to find connections that produce interesting sounds without damaging the chip. Using a resistor rather than a plain wire limits current and reduces the risk of a damaging short. When an interesting connection is found it can be soldered permanently or switched in and out. Multiple such resistors can cross-connect two different toys, enabling cross-modulation between their clocks. Collins cites Reed Ghazala as the founding father of circuit bending, attributing this philosophy as a powerful and creative tool for extracting unusual sounds from almost any found circuits.

Examples

Probe a Casio keyboard circuit board with a 1k ohm resistor between the ground bus and various component pads; when interesting glitch sounds appear, note the location and solder a switch there.

Assessment

Explain why circuit bending uses a resistor rather than a plain wire to probe connections, and describe how you would interconnect two toys to drive both from one clock.