Octave twelve Octave twelve An octave twelve is a type of 12-string guitar fitted with a short-scale neck and a small solid body. It is tuned one octave higher than a standard guitar giving it the tonal range of a mandolin and enabling a guitarist to achieve a mandolin sound without learning mandolin fingering. The effect is similar to that of capoing a standard 12-string guitar at its twelfth fret. However, unlike a standard 12-string guitar, the courses of strings tuned in unison, rather than in octaves. The octave twelve was invented by engineers at Vox, which sold the octave twelve as
String harmonic at one of the appropriate harmonic nodes for the note to sound. For example, to produce a pinch harmonic one octave higher than the fundamental of a string that is stopped at the third fret of a guitar, the string must be plucked halfway between the third fret and the bridge (the 15th fret, as the neck is logarithmic). Other overtones of the same fundamental note may be produced in the same way at other nodes along the string. The point where the string is plucked therefore varies depending on the desired note. Most harmonics have several accessible nodes evenly