A respected Greenwich, Connecticut, financial executive, Brian Lippey enjoys playing the guitar in his free time. Brian Lippey has a passion for the music and techniques of rock artists such as Eric Clapton and Robben Ford. One of the key implements in many classic rock guitarists’ arsenals is feedback, which was pioneered by Jeff Beck and Jimi Hendrix in the mid-1960s
A Scientific American article on the subject defines feedback as a mechanism through which an electronic device system sound is controlled. When an amplified instrument and a microphone are involved, high-pitched shrieks and interference can occur. As the sound from the amplified speaker reaches the microphone, another level of amplification occurs, which creates a loop of magnified sound. A gain system is often used to limit the potential for feedback and keep the sound “clean.”
Some creative rock guitarists take advantage of the vibrations of the electric guitar strings, as well as electromagnetic currents running from the pickups to the amplifier, to create harmonics that color the sound. The minutest fluctuations, properly amplified, can become loud feedback. This overlying harmonic can be abrasive or melodic, depending on the skill and intention of the guitarist.
Classic examples of feedback in rock include Hendrix’s rendition of the Star-Spangled Banner, in which harmonic feedback, sustained with vibrato, was used to mimic sounds of rapid movement and explosion.
