B7b9

B7b9 is B, D#, F#, A and C, a seven flat nine. The shape this page opens on is written x21212, lowest string first.

Also written B7(b9), B7-9 or B7♭9. The same chord either way; which spelling you meet depends on who wrote the chart.

There are 6 common shapes for B7b9 on the guitar, and 38 derived voicings in 4 families.

The common shapes, written lowest string first: x21212, 7675xx, xx7878, 797878, x-x-9-8-10-8, x-14-13-14-13-14.

Shell. Root, third and seventh: the guide tones fix the quality, so the fifth is dropped. That is what leaves a string free, so pick a tension to put on top. B7b9 has x2121x, 7675xx, x-x-9-8-10-8, x-14-13-14-13-x.

Drop 2. A close-position chord with the second voice from the top lowered an octave. Sits on four adjacent strings. B7b9 has x2121x, 7675xx, x-x-9-8-10-8, x-14-13-14-13-x, xx1415, 5314xx, x3744x, xx7547.

Drop 3. The third voice from the top lowered an octave. The dropped voice becomes the bass, which is why a string is skipped. B7b9 has 5x141x, x3x445, 7x754x, 8-x-9-8-10-x, x-12-x-8-12-8, 11-x-10-14-12-x, x-14-x-14-13-11, x-6-x-5-10-7.

Rootless. The root left to the bass player. Frees a finger for a tension. B7b9 has xx1212, x3424x, xx4545, x6757x, xx7878, x-9-10-8-10-x, x-x-10-11-10-11, x-12-13-11-13-x.

Tensions. A shell of B7b9, root, third and seventh, leaves a string free, and the tones that belong over it are the #11 (E#), the b13 (G) and the 13 (G#).

The common shapes and the derived voicings come from different places, and both are explained in where the chords and the theory come from.