The bajo sexto is an instrument with 12 strings that is very similar to a traditional guitar. "Bajo sexto" translates from Spanish into English as under six, and is also known in English as the lower sixth guitar because it plays an octave below a traditional guitar. The bajo sexto is primarily used in Tex-Mex and Tejano music, usually accompanied by other instruments such as the accordion and the drums.
Learn how to use your tuner. Generally, digital tuners display a red light on the left for a flat note, a red light on the right for a sharp note and a green light for an in-tune note. Adjusting your peg counterclockwise will correct a flat note while adjusting your peg clockwise will correct a sharp note.
Strum the bottom course. These are the two strings at the bottom of the bajo sexto as you hold it. Do not hold the frets while you tune. Adjust the strings until your tuner registers an F on the these two strings in perfect tune.
Play the next course in unison. Adjust the strings until your tuner registers a C in perfect tune.
Pick the third course. Adjust the strings until your tuner registers a G on strings five and six in perfect tune.
Pluck the stings in course four separately. Both strings must be tuned to a D, though they will be one octave apart.
Pick the next two strings, again separately. These strings, nine and 10, will tune to an A.
Play strings 11 and 12 separately. Tune these strings to an E, one octave difference.
Over adjusting your pegs may break the strings.