Twelve-string bass


The 12-string bass is an electric bass with four courses of three strings each, though they occasionally have six courses of two strings.
Normal tuning is eeE-aaA-ddD-ggG, with one string of each course tuned similarly to the corresponding string of the four-string bass, and the remaining two strings tuned to the octave.
The first known 12-string bass guitar, the "Hamer Quad," was designed by Jol Dantzig and built in 1977 for Tom Petersson by Hamer Guitars. Petersson's Cheap Trick bandmate Rick Nielsen reports that Petersson first conceived of the instrument in 1973, and worked with Hamer over the next few years refining the design.

Notable players

Basses with 12 strings and different layouts have been built.
A bass with six two-string courses was played by John Paul Jones of Led Zeppelin.

Six-course bass