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
Vibrato systems for guitar An advantage or disadvantage, depending on taste, is string resonance audible at several fret positions where a simple relation exists between the length to the fret and the string length behind the bridge (for instance 48:12 = 4:1). At those positions, a high overtone rises in volume. This becomes clearer with an over-driven guitar sound. The overtone might sound odd, but it still has a harmonic relation to the note, so is not out of tune related to the open string. For staccato playing, it can be annoying. Muting the strings behind the bridge with felt or other material solves