Kevin Shields’ characteristic My Bloody Valentine guitar sound is often described as if it came from an enormous collection of effects.
One of its essential gestures is much simpler.
Shields loosens the tremolo arm of a Fender Jazzmaster, holds it while strumming and continuously moves the pitch slightly during the chord. Combined with open voicings and reverse reverb, the guitar stops behaving like a stable harmonic object.
The technique is sometimes called glide guitar.
What interests me is that the sound depends on instability at the source.
A normal approach would record a stable guitar and add modulation afterwards.
Shields physically changes pitch while the string is sounding.
Every strum therefore contains movement that cannot be completely separated from the performance.
That makes the famous wall of sound less complicated than it appears.
The ear hears layers because one chord contains several slightly shifting pitch relationships.
A guitar can begin sounding like several copies of itself drifting across tape.
There is an important production lesson hidden there.
Complexity does not always require more tracks.
Sometimes one unstable sound contains more information than ten perfectly stable ones.