B13

B13 is B, D#, F#, A, C# and G#, a dominant thirteenth. The shape this page opens on is written x21244, lowest string first.

Note by note. B is the root, D# is the major third, F# is the fifth, A is the flat seventh, C# is the ninth and G# is the thirteenth.

Also written Bdom13 or B dominant 13. The same chord either way; which spelling you meet depends on who wrote the chart.

There are 7 common shapes for B13 on the guitar, and 47 derived voicings in 4 families.

One note away. Change a single note of B13 and you have Bmaj13 (with one note moved), B69 (with one note taken away), B9 (with one note taken away) or B9#11 (with one note moved).

In which keys. Every note of B13 belongs to C# minor (the ♭VII) and E major (the V).

The common shapes, written lowest string first: x21244, x21224, 222244, 746445, 766675, 777899, 797897.

Under the hand. None of the shapes for B13 uses an open string, so every one of them is movable; the lowest sits at the 1st fret. 6 of the 7 need a barre. Together they cover the neck from the 1st fret to the 9th.

Where it goes. B13 is the V of E, and that is where it goes if it goes anywhere: the third and the flat seventh are a tritone apart, and both resolve by a semitone into E.

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. B13 has x2x244, 7x789x.

Drop 2. A close-position chord with the second voice from the top lowered an octave. Sits on four adjacent strings. B13 has x0110x, xx6445, 5664xx, xx7897, x-12-13-13-12-x, 4212xx, xx1204, x2624x.

Drop 3. The third voice from the top lowered an octave. The dropped voice becomes the bass, which is why a string is skipped. B13 has 4x120x, x2x244, 5x644x, x-11-x-8-10-7, 7x789x, 11-x-9-13-10-x, x-12-x-13-12-11, x6x495.

Rootless. The root left to the bass player. Frees a finger for a tension. B13 has x0112x, xx4244, xx6645, xx7899, x9789x, x-12-13-13-14-x, xx1224, x0x142.

Tensions. A shell of B13, root, third and seventh, leaves a string free, and the tones that belong over it are the #11 (E#).

What kind of chord this is. B13 is a dominant chord — root, major third, fifth, minor seventh. dominant seventh chords on every root, and what they are for.

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