The 12 string acoustic guitar originated in the 1920's and has 12 strings in 6 courses, which produces a richer, more ringing tone than a standard six-string guitar. Essentially, it is a type of guitar with a natural chorus effect due to the subtle differences in the frequencies produced by each of the two strings on each course. Used by a host of folk and rock musicians including Bob Dylan, Arlo Guthrie, Keith Potger, John Denver, Gordon Lightfoot, Ben Woodward, Pete Seeger, Noel Paul Stookey, and Warren Zevon. Seems to have been invented in more than one country. The prominent inventors were in Brazil and the USA.Tuning:Nowadays E3 E2, A3 A2, D4 D3, G4 G3, B3 B3, E4 E4, but traditionally C3 C2, F3 F2, A#4 A#3, D#4 D#3, G3 G3, C4 C4 or B2 B1, E3 E2, A4 A3, D4 D3, F#3 F#3, B4 B4 to reduce the high tension.Strings/Courses:12/6Further notes:Always use steel strings.Scale Length:650mm""