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.
Bb69 is Bb, D, F, G and C — Bb6 with the ninth added as well.
It sounds wide and entirely at rest. The modern way to voice a tonic when a triad is too bare and a maj7 too pointed.

| Bb | D | F | G | C |
|---|---|---|---|---|
| 1 | 3 | 5 | 6 | 9 |
Tonic — it commits to nothing.
Also written Bb6/9, Bb6add9 or Bb six nine. 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.
Bb69 has 5 of them, on the middle four strings, the bottom four strings, the top four strings and strings 6-4-3-2, from open position up to the 12th — all in one inversion, so the bass note never moves. The one to learn first is the Bb shape at the nut, which is the easiest grip here.
Start with x-13-10-12-11-10 — no barre. 1 of the 8 shapes here sits in open position. 7 of the 8 need a barre. Together they cover the neck from the 1st fret to the 13th.
| Frets | Where | Bass | Top | Hand |
|---|---|---|---|---|
| x10011 | open position | Bb, root position | F | barred |
| x33333 | 3rd fret | C, 9th in the bass | G | barred |
| 655566 | 5th fret | Bb, root position | Bb | barred |
| xx8788 | 7th fret | Bb, root position | C | barred |
| x88788 | 7th fret | F, 2nd inversion | C | barred |
| x-10-10-10-11-10 | 10th fret | G, 6th in the bass | D | barred |
| x-13-10-12-11-10 | 10th fret | Bb, root position | D | all fretted |
| x-13-12-12-13-13 | 12th fret | Bb, root position | F | barred |
The same notes rebuilt from scratch give 15 drop 2, 10 drop 3, 15 rootless and 4 open string voicings, each on its own page.
Tensions. A shell of Bb69, 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 Bb69 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 Bb69 belongs to C minor (the ♭VII), D minor (the ♭VI), Eb major (the V), F major (the IV), G minor (the ♭III) and Bb major (the I).
Bb69 is every note of the Bb major pentatonic, and nothing else. It also sits inside Bb major, Bb lydian, Bb mixolydian and Bb lydian dominant.
Change one note of Bb69 and you have Bbmaj9 (the sixth becomes a major seventh), Bbmaj13 (add the major seventh), Bbm69 (the major third becomes a minor third), Bbadd9 (drop the sixth), Bb6 (drop the ninth) or Bb9 (the sixth becomes a flat seventh).
Bb69 is a major chord — root, major third, fifth. Major chords on every root.
On Bb69’s sound and use this page follows Mark Levine, The Jazz Piano Book (Sher Music, 1989). 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.