Acoustic bass guitar of acoustic bass guitars. The bajo sexto, with six pairs of strings, resembles a twelve-string guitar tuned an octave lower. The heavy gauge strings generate a large string tension, yet the guitar is built relatively lightly. Musicians began to use the bajo sexto in Texas in the 1920s with the rise of "Tex-Mex" music, and remains in common use to play parts that would be played by the piano in traditional American popular music. It matches the standard tuning of a 12-string guitar, one octave lower. The tuning of these instruments is (capital letters are an octave lower than small
Eleven-string alto guitar 11-string alto guitar. This design introduced two main elements. The first was to provide conventional lute tuning by tuning the first six strings a minor third higher (hence the name "alto guitar"). It is equivalent to putting a capo on the third fret of the normal prime guitar. The second element was to add five extra strings to accommodate low notes. The typical 11-string alto guitar tuning is (from low to high strings): Bb1 C2 D2 Eb2 F2 G2 C3 F3 Bb3 D4 G4. Current luthiers who build 11-string alto guitars, primarily located in Sweden, include Heikki Rousu and Roger