An open string left ringing against a fretted grip. Because it costs no finger, it sounds a note the closed shape has none left for -- a tension on top, or a pedal root underneath. Either a familiar grip with open strings added, or a shape so sparse the open strings carry the chord. These belong to their key rather than to a shape, so D, A, G and E have many and Eb a handful.
Bbmaj11 is Bb, D, F, A, C and Eb — Bbmaj9 with the eleventh added — the note that fights the major third.
It sounds unsettled, and grittier than the rest of the major family. Most players drop the third or raise the eleventh instead, which is how you arrive at a sus chord or at maj7♯11.

| Bb | D | F | A | C | Eb |
|---|---|---|---|---|---|
| 1 | 3 | 5 | 7 | 9 | 11 |
Tonic, awkwardly — the eleventh sits a semitone above the third.
Also written BbM11, BbΔ11 or Bb major 11. The same chord either way; which spelling you meet depends on who wrote the chart.
An open string left ringing against a fretted grip. It costs no finger, so it can sound a note the closed shape has none left for: a tension on top, or a pedal root underneath.
These belong to their key rather than to a shape: they cannot be moved up the neck. D, A, G and E have many; E♭ has a handful.
Bbmaj11 has 5 of them, on strings 5-4-3-2-1, the top four strings, the bottom four strings, strings 6-4-3-2 and the middle four strings, from the 3rd fret up to the 5th — every inversion the chord has: D in the bass and A in the bass. The one to learn first is the A shape at the 3rd fret, which is the easiest grip here.
Start with 6x0545 — no barre and 1 open string. 1 of the 8 shapes here sits in open position. 4 of the 8 need a barre. Together they cover the neck from the 1st fret to the 15th.
| Frets | Where | Bass | Top | Hand |
|---|---|---|---|---|
| x11231 | 1st fret | Bb, root position | F | barred |
| 6x0545 | open position | Bb, root position | A | 1 open string |
| 65xx45 | 4th fret | Bb, root position | A | all fretted |
| 667766 | 6th fret | Bb, root position | Bb | barred |
| 667768 | 6th fret | Bb, root position | C | barred |
| x-x-8-8-10-10 | 8th fret | Bb, root position | D | all fretted |
| x-13-12-14-11-11 | 11th fret | Bb, root position | Eb | all fretted |
| x-13-13-14-15-13 | 13th fret | Bb, root position | F | barred |
The same notes rebuilt from scratch give 6 shell, 13 drop 2, 8 drop 3 and 25 rootless voicings, each on its own page.
Tensions. A shell of Bbmaj11, root, third and seventh, leaves a string free, and the tones that belong over it are the 13 (G).
How you get to it. The turn that lands on Bbmaj11 is Cm7 to F7 — the ii and the V of Bb — and F7 shares its third and seventh with Cm7, so the hand barely moves between them.
In which keys. Every note of Bbmaj11 belongs to G minor (the ♭III) and Bb major (the I, the tonic).
Every note of Bbmaj11 is in Bb major.
Change one note of Bbmaj11 and you have Bbmaj9 (drop the fourth), Bbmaj13 (the fourth becomes a sixth) or BbmMaj11 (the major third becomes a minor third).
Bbmaj11 is a major chord — root, major third, fifth. Major chords on every root.
On Bbmaj11’s sound and use this page follows Barrie Nettles & Richard Graf, The Chord Scale Theory and Jazz Harmony (Advance Music, 1997). 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.