A 7b9 Chord on Puerto Rican Cuatro
Play A 7b9 on Puerto Rican Cuatro: diagrams, finger positions, intervals, and every voicing up and down the neck for this instrument.
The A 7b9 chord is an extended or altered dominant that stacks ninths, elevenths, thirteenths, or chromatic tensions over a dominant-seventh core. It is built from the notes A, A#, C#, E, G. This page shows how to play A 7b9 on Puerto Rican Cuatro with clear fretboard diagrams and suggested finger positions.
The A and G strings ring open in the lowest shape, with the remaining notes fretted at fret 8 over a 3-fret stretch. A falls on the B string. It sounds from A3 up to A#4.
Puerto Rican Cuatro is strung in five courses of two, the lower two paired an octave apart, so each stopped note here sounds as two — which is why the shape rings thicker than the same grip on a single-strung instrument.
Browse alternate voicings to find the one that sits best under your fingers, then compare it with the other chord types built on A or explore the same shape in nearby keys. The diagrams list the notes in each voicing so you can connect the shape to the theory behind it.