A
pinch harmonic[dubious – discuss], or
pick harmonic[1], also known as a
scream,
squealie[citation needed] or
squealer[citation needed] is a
guitar technique (typically
electric guitar) pioneered
[citation needed] by
Roy Buchanan in which the player's thumb or index finger (on the picking hand) slightly catches the string after it is picked, cancelling the
fundamental of the string, and letting one of its
harmonics ring out. This creates a high
pitched sound in any position. By using string bending, a
whammy bar, a
wah-wah pedal, or other effects,
electric guitarists are able to modulate the pitch, frequency, and
timbre of pinch harmonics, resulting in a variety of sounds, the most common being a very high-pitched squeal. Pinch harmonics are generally considered a type of
artificial harmonic, although they are played completely differently. It is worth noting that there is no actual
pinching involved in playing this kind of harmonic.
Unlike natural harmonics, which may only be produced at certain string positions, pinch harmonics can be sounded at any fret position along the neck of the guitar. Pinch harmonics also allow the guitarist's fretting hand to stay in position while higher notes than are normally possible at that position are sounded. In addition to expanding the accessible range of pitch, pinch harmonics can be used as unaccompanied tones in a solo or as filler notes between deeper chords.
The technique is possible on any fretted stringed instrument, but is most widely employed by electric guitarists, especially in heavy metal and rock music where heavy distortion ensures that the otherwise subtle harmonic is greatly amplified. An identifiable signature was pioneered by such artists as Eddie Van Halen and Steve Vai, utilizing the whammy bar, high gain amps, and the pinch harmonic. This ended up producing wild, screaming, horse-like wails from the instrument. Steve Vai composed a track named "Bad Horsie" which uses heavy pinch harmonic techniques. A pinch harmonic was used at the beginning of the second solo of Pink Floyd's Comfortably Numb.
Pinch harmonics are used extensively in death metal, especially in the sub-genre Brutal death metal. The technique's use in death metal is notable in that pinch harmonic notes are included in riffs, rather than being reserved for solos. Combined with the rather low tunings most of these guitarists use, and the fact that they are usually played by both rhythm guitarists (if there are two), the pinch harmonic notes leap out, creating more complex and twisted melodic contours than otherwise possible. The technique is also used commonly in other sub-genres of heavy metal, particularly by guitarists such as K. K. Downing[citation needed], Glenn Tipton, Zakk Wylde, Mick Thomson, and Dimebag Darrell. One guitarist of the rock genre who is widely known for his use of pinch harmonics is Billy Gibbons of ZZ Top, who uses them numerous times in nearly every guitar solo he plays.
