Circuit bending is rather nicely described in the Wikipedia (at http://en.wikipedia.org/wiki/Circuit_bending) as the ‘creative customization’ of electronic devices such as ‘low voltage, battery-powered guitar effects, children’s toys and small digital synthesizers to create new musical or visual instruments and sound generators’.
The true method of approaching circuit-bending (IMHO, as they say) is experimental, without having – or without deliberately using – knowledge of the circuit you’re working on; the enjoyment of chance discovery is an important element of the experience, which is why I have distinguished it in my projects from ‘modification’, where I felt a knowledge of electronics and the circuitry being worked on was a useful thing.
The guru of circuit-bending is Qubais Reed Ghazala (http://en.wikipedia.org/wiki/Reed_Ghazala), and his book Circuit-Bending : Build Your Own Alien Instruments (pub. Wiley, 2005, ISBN 978-0764588877) is the standard work on the subject. It explains how he came to discover the idea of ‘bending’ – leaving a small, battery-powered amplifier in a desk drawer, the power on and the back off, where a metal object in the drawer touched parts of the circuit and produced marvellous noises – illustrates some of the instruments he has created over the years, and gives detailed instructions on how to ‘bend’ some popular electronic instruments and toys available today.
If you’re not able to obtain a copy of Reed Ghazala’s book, you can read about it on his website at www.anti-theory.com, and follow a step-by-step tutorial at www.anti-theory.com/soundart/circuitbend/cb01.html.
A fabulous website for electronic music fans is www.electro-music.com; in this case a browse through their Circuit-bending forum at http://electro-music.com/forum/forum-113.html will throw up heaps of advice on what devices to get and what do with them once you’ve got them. This may at the outset involve only making sure it’s using batteries, not plugged into the mains, switching it on, wetting your finger and poking the circuit board until something interesting happens.
So, if you’d like to get into electronic music, but are put off because you know nothing about electronics, then circuit-bending may be the thing for you, as Ghazala emphasises the fact that no knowledge is required! Right at the beginning of Chapter 1 of his book he tells the story of taking his first circuit-bent instrument to school, ‘synthesizing birds, helicopters, and police sirens on the instrument, and running electricity through several people at a time so that we could play the device by touching each others’ bare flesh.’ His teacher is very impressed, looking at the dials and switches and hearing the extraordinary sounds. ‘Mr Ghazala,’ he says, ‘I didn’t know you knew anything about electronics.’ ‘I leaned forward’, Ghazala tells us, ‘looked him straight in the eye, and said, ‘I don’t.’
At the time of writing I haven’t begun any of my planned projects in circuit-bending, but I’ve been collecting some suitable devices to work on. I’ll report on these as soon as I’ve been able to get started; in the meantime, here are some of the items I’ve acquired. I’m particularly interested in the human voice in this context, so you will see a Texas Instruments ‘Speak and Spell’ amongst them, a Vtech ‘Alphabet Apple’ and a Casio SK-60, famous for its ‘human voice’ presets.