An octave twelve is a type of 12-string guitar fitted with a short-scale neck 15.5 inches (39 cm) and a small solid body.
The effect is similar to that of applying a capo to a standard 12-string guitar at its twelfth fret.
[1][failed verification] However, unlike a standard 12-string guitar, the courses of strings are tuned in unison rather than in octaves.
[citation needed] The octave twelve was invented by engineers at Vox, which sold the octave twelve as the mando-guitar from 1964 to 1968. Notable users of the mando-guitar included Brian Jones of the Rolling Stones.
Most modern octave twelves are modelled after the distinctive body shape of the Vox mando-guitar.