A component found on many electric guitars that allows players to produce a vibrato effect — a series of pitch changes, up or down, on notes. Originally conceived as a replacement for a guitarist’s subtle finger movement on the frets, this effect can be used for gentle or extreme pitch changes. A common slang term for the vibrato tailpiece and its control arm is “whammy bar.”
Inventors have been trying to add vibrato to electric guitars since they first appeared on the scene. The Vibrola, a 1935 guitar made by Rickenbacker (invented by Doc Kauffman, who would later become Leo Fender’s first partner), was equipped with a motorized vibrato tailpiece that used cams to stretch and loosen the strings. It didn’t work very well. Les Paul claims to have experimented with vibrato controls in the 1930s as well.
Ultimately, manufacturers generally adopted the practice of replacing the guitar’s bridge with a spring-loaded mechanism that can stretch the strings (to raise pitch) or loosen them (to lower pitch). Commonly these changes are made by pushing or pulling on a control arm that hangs below the strings, within easy reach of the guitarist’s right hand. Many historians agree that the first commercially successful unit was designed and marketed by Paul Bigsby in the late 1940s.
The challenge of changing pitch by stretching and loosening strings lies in getting the strings to return to their normal intonation, or tuning, after using the vibrato. A solution was introduced in “floating” vibrato systems, which allow both upward and downward bends and were designed with locking nuts that allow players to “lock” the strings in tune.
Important clarification: many guitarists and manufacturers mistakenly refer to “vibrato,” meaning variations in pitch, as “tremolo,” which means changes in amplitude, or volume. Fender and Floyd Rose both call their vibrato tailpieces “tremolo,” while some amplifiers provide an electronic tremolo unit, which guitarists (following Fender’s lead) incorrectly call a “vibrato.”