Methods · Entry 01
Preparing a Guitar
Objects placed between and on the strings turn a familiar instrument into a set of unpredictable resonators — but not everything is as uncontrollable as it sounds.
What Changes When You Alter the String
A standard steel-string guitar is built around one principle: a string is plucked, decays, and the body reinforces that decay at a known frequency. Prepare it — place a bolt across the strings near the twelfth fret, wedge a comb between the wound bass strings, lay a thin strip of metal along the high E — and the principle dissolves. Each object damps, buzzes, splits, or multiplies the string's vibration in ways that depend heavily on mass, contact area, and position along the scale length.
The vocabulary here is John Cage's, first formalised in his Bacchanale of 1940, written for a dance performance that required a percussion orchestra the venue couldn't fit. His subsequent prepared-piano scores notated preparations precisely: bolt, rubber, screw, and distance from the nut, in fractions of an inch. Guitar preparation has never achieved that level of codification, partly because guitar strings are more mobile than piano strings and partly because the results vary with the instrument. The same bolt on two different guitars — different bracing patterns, different top thickness — produces different results. This is a constraint worth knowing before you record.
What Holds and What Wanders
Some outcomes are reliably repeatable. A hard object resting across all six strings at a fret produces a percussive thud on the plucked side and a faint residual on the body side, and this ratio is stable between sessions. A large bulldog clip attached to a single string loads that string's mass and drops its pitch by a predictable interval, though the interval shifts if the string has been played enough to stretch. A slide placed horizontally across the strings and bowed produces a continuous tone, and the tone's pitch is determined by where the slide crosses — treat that as a moveable fret and the preparation behaves almost like a conventional instrument. Bowing a string in this configuration sustains a note the instrument would otherwise be incapable of holding.
The unstable outcomes are equally important. Objects that only partially contact a string — a thin paper strip, a piece of rubber not quite under tension — produce a buzz whose character is unpredictable across takes. The buzz is not random exactly: it is sensitive to the player's finger pressure, room humidity, and small variations in pick angle. Recording three identical passes with a paper preparation will give three perceptibly different surfaces, which is useful if textural variation across a layer is the goal and costly if you need consistent repetition. Knowing which preparations are stable and which are aleatory is the first practical taxonomy a method demands.
Position matters as much as material. An object placed at the twelfth fret sits at the string's exact midpoint, so it will damp the fundamental while leaving the second harmonic relatively free — the result reads harmonically simple even when the timbre is heavily altered. Move the same object toward the bridge and you damp a different set of harmonics; the sound becomes stranger, more metallic, harder to place in a harmonic context. This interaction between preparation position and harmonic series is the core tool, and it is systematic enough to map in advance.
The Recording Question
A prepared guitar is not loud. Objects damp resonance, and a body that resonates less puts out less sound pressure. Close microphone placement is almost always necessary, which means the recording captures the mechanics — the creak of a shift, the rattle of a loosely placed piece — alongside the intended sound. In much practice, that is not a problem: the mechanical noise is part of the texture. But it requires the player to decide whether the accidental sounds are material or interference, and to hold that decision consistently through a session. A preparation that generates useful rattle on one pass and distracting clatter on the next is a preparation whose contact point needs refining.
The most useful summary is this: hard objects in firm contact are stable; light objects in partial contact are not; position along the string determines harmonic character; and close-miking means every mechanical event is on record. Work within those four parameters and the prepared guitar stops being an instrument that surprises you and becomes one that surprises only when you intend it to.
