Distortion

What it means

Distortion arises when a signal is amplified beyond the limit of what a device can transmit cleanly. The waveform is clipped in the process, and additional partials arise that were not contained in the original sound. The tone thereby becomes richer in overtones, denser, more aggressive, and at the same time rings on longer, because the differences in volume are compressed. What in audio engineering was at first a fault became a means of shaping in music.

Musical use

Distortion shapes the sound of large parts of popular music since the middle of the twentieth century, above all with the electric guitar. It changes not only the colour but the feel of playing: notes sustain longer, small movements of the hand become audible, and chords with many notes become muddy, because the additional partials enter into relation with one another. Distorted styles therefore often work with few notes and open intervals. In art music and in electronic music, distortion is likewise used, there usually as one of many sound treatments.

Distortion arises when an amplifier or an effects unit overdrives the signal and the waveform is clipped. In the process additional overtones arise that make the sound rougher, louder, and denser. In the rock music of the 1960s it became a stylistic device; dedicated pedals such as fuzz, overdrive, and distortion differ in the degree of distortion. Because the third sounds unclean under heavy distortion, guitarists often use power chords.

Performance practice

Bear in mind that distortion reduces dynamics: what is played quietly sounds about as loud as a strong attack. Shape therefore through articulation and damping rather than through strength of attack. Damp unused strings consistently, because otherwise everything rings along. In heavily distorted sounds, choose close chords with care — fifths and octaves stay clear, dense chords blur. Settle the settings before rehearsal and change them during a piece only at planned places. Watch the volume in the room and hearing protection.

Bear in mind also that distortion enriches the overtones so that intervals sound different from the undistorted sound: thirds become rough, fifths and octaves stay clear. Check the intonation, because deviations stand out more clearly.