The Fault That Became the Sound

The electric guitar began as a volume control. In the swing bands of the 1930s the guitar was a rhythm instrument, strummed four to the bar, and against a brass section it was felt more than heard. The problem was simple to state: make it louder without making it a different instrument.

The solution was the magnetic pickup. A steel string vibrating above a magnet wrapped in fine wire disturbs the magnet's field and induces a tiny current that copies the string's motion. Feed that to an amplifier and a loudspeaker and the guitar can be as loud as you like. George Beauchamp and Adolph Rickenbacker's company in Los Angeles put the idea into production in the early 1930s, on a cast aluminium lap steel guitar nicknamed the Frying Pan. Gibson's ES-150, an archtop with a pickup, followed in 1936.

The player who showed what it was for was Charlie Christian. From 1939, in Benny Goodman's band, he played single-note lines on an ES-150 that phrased like a saxophone, and for the first time the guitar stood in front of a band rather than inside it. The pickup had been a volume fix. It turned out to be a new voice.

Then came the howl. A hollow guitar body is a resonator, which is the point of an acoustic guitar, but put it in front of a loud amplifier and the body picks up the sound from the speaker, the strings shake, the pickup hears them, and the whole system rings out of control. Engineers call that feedback, and for anybody trying to play loud it was the main obstacle.

The answer was to take the resonance away. Les Paul built a guitar on a solid block of pine that he called the Log. Leo Fender designed a solid-body guitar for factory production, sold from 1950 as the Esquire and the Broadcaster and soon renamed the Telecaster, and followed it with the Stratocaster in 1954. Gibson's Les Paul model arrived in 1952. A solid slab barely moves in sympathy with the speaker, so it can be played loud, and its notes sustain longer. The makers had, they thought, made the instrument clean.

The players went the other way.

A valve amplifier driven past what it can reproduce cleanly does not simply fail. It flattens the peaks of the waveform gradually, adding harmonics and squeezing the dynamics, so a note grows thicker, more sustained and more aggressive the harder it is pushed. That is overdrive. To an amplifier designer it is distortion, a defect to be avoided by building in headroom. To a guitarist in a loud room it was a sound.

The history of how it came to be wanted is a history of damage. For the sound of You Really Got Me in 1964, Dave Davies of the Kinks slit the speaker cone of a small amplifier with a razor blade, so that it rattled and buzzed on every chord. Gibson had been selling a fuzz box, the Maestro Fuzz-Tone, since the early 1960s, without much success. In 1965 Keith Richards used one to sketch the riff of Satisfaction, as a guide for a horn section to be added later. The horns never came, the record went to number one, and the Fuzz-Tone suddenly sold.

Feedback followed the same path. The loop that the solid body was partly built to suppress turned out to be playable: stand at the right angle to the speaker, hold a note, and it swells into a sustained tone of its own, sometimes jumping to a harmonic above. The Beatles put a deliberate burst of it at the start of I Feel Fine in 1964. By the time Jimi Hendrix played The Star-Spangled Banner at Woodstock in 1969, feedback was being shaped into sirens and falling bombs with the precision of a phrase.

That is an unusual history for an instrument. Most instruments are refined towards an ideal their makers can describe. The electric guitar's makers described loud and clean. Its players kept the loud, threw away the clean, and built the instrument's defining sound out of the behaviour its designers had spent years trying to prevent.