A bajo sexto (Spanish: "lower sixth") is a type of 12 string guitar, fused with a bass, used in Mexican music. It is used primarily in norteño music of northeastern Mexico and across the border in the music of south Texas known as "Tex-Mex," "conjunto," or "música mexicana-tejana". Norteño (literally meaning northern in Spanish; also known as conjunto) is a genre of Mexican music. ... Tejano[1] (Spanish for Texan) or Tex-Mex[2] music is the name given to various forms of folk and popular music originating among the Hispanic-descended Tejanos of Central and South Texas. ...
The bajo sexto sound provides a strong rhythm in the lower pitched end of a Tejano band and also provides a strong projection of chord changes across songs.
Bajo sextos are tuned: M,O,F,U,G,A,E,R (from highest to lowest string)