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
Nine-string guitar 25.5"). Tuning the highest string to an A4 or higher can be accomplished with a shorter scale length and/or a thinner string such as a .008 or .007. Extended range nine-string guitars also sometimes have a multi-scale fingerboard design where the bass strings will be longer than the treble strings, which helps with proper intonation of the lower strings, improves string tension balance across the strings, improves harmonic overtones, overtone series, and inharmonicity. Notable guitar players of double-stringed nine-string guitars: Notable guitar players of extended-range nine-string guitars: Nine-string guitar A nine-string guitar is a guitar with nine strings instead of