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
Fret generally perpendicular to the instrument's neck centerline and parallel to each other, on a "fanned" fretboard, the frets are angled (spread like a fan) with only one center fret perpendicular to the neck’s centerline. This gives the lower-pitched strings more length and the higher strings shorter length (comparable to a piano or a harp where heavier strings have different lengths). The idea is to give more accurate tuning and deeper bass. Some think that fanned frets might be more ergonomic. Fanned frets first appeared on the 16th century Orpharion, a variant of the cittern, tuned like a lute. John Starrett