Reverse tape effects are special effects created by recording sound onto magnetic tape and then physically reversing the tape so that when the tape is played back, the sounds recorded on it are literally heard in reverse.

Although the ability to reverse the playback of recorded sounds had been known since the early days of gramophone records and can be achieved by simply placing the needle on the record and spinning it counter-clockwise, reverse effects were regarded largely as a curiosity and were little used until the 1950s.

It was not until the advent of magnetic tape in the 1950s and the consequent development of the experimental music genre known as musique concrete that reversed sound effects came into more widespread use as a musical effect.

The technique became especially popular during the psychedelic music era of the mid-to-late 1960s, when musicians and producers exploited a vast range of special audio effects in an attempt to simulate the auditory effects of the LSD experience.

An good example of the use of reverse tape effects is the song "Roundabout" (1972) by the British progressive rock group Yes. The song begins with a sound which gradually fades in, and then ends suddenly, changing abruptly into guitar music, performed by guitarist Steve Howe.

The 'fade-in' sound is a minor chord (played on a grand piano by keyboardist Rick Wakeman) which was sounded and allowed to fade to slience. The tape of this piano chord was then reversed by producer Eddie Offord and carefully edited into the track. With the fading piano sound is thus reversed, it slowly builds up in volume before ending suddenly, at which point Offord edited it seamlessly into the first notes of Howe's guitar introduction. This disctinctive effect is heard several times during the introduction and its reprise.

One of the best known examples of music featuring reverse tape effects is the Doctor Who theme (1963), composed by Ron Grainer and realised electronically by Delia Derbyshire of the BBC Radiophonic Workshop.

Another famous example of the use of reverse tape effects is The Beatles' 1967 single "Strawberry Fields Forever, written by John Lennon and produced by George Martin. During the verses, Lennon's voice is accompanied by a series of rapid 'swooshing' sounds; these are actually the sounds of Ringo Starr's drum and cymbal accompaniment. These patterns were carefully pre-recorded, the tape reversed and the reversed percussion effects meticulously edited into the master tape to synchronise with the music.

Several other Beatles songs of the period -- including George Harrison's Love You To (1966) -- also feature recordings of electric guitars which have been reversed.

See also

• Tape loop
• Backmasking