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.
Bmaj13 is B, D#, F#, A#, C# and G# — Bmaj9 with the thirteenth on top, and the eleventh left out.
It sounds full and wide open. Six notes into four fingers means something goes: keep the third, the seventh and the thirteenth.

| B | D# | F# | A# | C# | G# |
|---|---|---|---|---|---|
| 1 | 3 | 5 | 7 | 9 | 13 |
Tonic — the major sound with most of the scale showing.
Also written BM13, BΔ13 or B major 13. The same chord either way; which spelling you meet depends on who wrote the chart.
Root, third and seventh. The third and seventh, the guide tones, are what make the chord major, minor or dominant, so the fifth can go: it says nothing the symbol needs.
Three notes means a spare string, which is the real point. Put a tension on it.
Bmaj13 has 2 of them, on strings 5-3-2-1 and strings 6-4-3-2, from the 2nd fret up to the 7th — all in one inversion, so the bass note never moves. The one to learn first is the B shape at the 2nd fret.
Start with x22344 — no barre and down at the nut. None of the shapes for Bmaj13 uses an open string, so every one of them is movable; the lowest sits at the 2nd fret. 4 of the 6 need a barre. Together they cover the neck from the 2nd fret to the 14th.
| Frets | Where | Bass | Top | Hand |
|---|---|---|---|---|
| x22344 | 2nd fret | B, root position | G# | all fretted |
| 766676 | 6th fret | B, root position | A# | barred |
| 778897 | 7th fret | B, root position | B | barred |
| x-11-9-9-11-11 | 9th fret | G#, 13th in the bass | D# | barred |
| x-14-13-13-11-11 | 11th fret | B, root position | D# | all fretted |
| x-14-11-13-11-11 | 11th fret | B, root position | D# | barred |
The same notes rebuilt from scratch give 13 drop 2, 8 drop 3 and 24 rootless voicings, each on its own page.
Tensions. A shell of Bmaj13, root, third and seventh, leaves a string free, and the tones that belong over it are the #11 (E#).
How you get to it. The turn that lands on Bmaj13 is C#m7 to F#7 — the ii and the V of B — and F#7 shares its third and seventh with C#m7, so the hand barely moves between them.
In which keys. Every note of Bmaj13 belongs to Eb minor (the ♭VI), F# major (the IV, the subdominant), Ab minor (the ♭III) and B major (the I, the tonic).
Every note of Bmaj13 is in B major and B lydian.
Change one note of Bmaj13 and you have Bmaj9 (drop the sixth), Bmaj11 (the sixth becomes a fourth), B69 (drop the major seventh) or B13 (the major seventh becomes a flat seventh).
Bmaj13 is a major chord — root, major third, fifth. Major chords on every root.
On Bmaj13’s sound and use this page follows Ted Pease & Ken Pullig, Modern Jazz Voicings (Berklee Press, 2001). The shapes and the derived voicings come from different places, and both are explained in where the chords and the theory come from.
Shows each chord the way this style would voice it, and marks which of its alternatives belong to the idiom.