Bb is Bb, D and F.
It sounds plain and completely at rest. The reference every other chord on this page is a modification of.
Tonic — the chord a progression stops on.

| Bb | D | F |
|---|---|---|
| 1 | 3 | 5 |
Also written Bbmaj, BbM or Bb major. The same chord either way; which spelling you meet depends on who wrote the chart.
Bb in 2nd inversion puts F in the bass instead of Bb, the 5th of the chord. The notes are the same; what changes is what the bass line does, which is most of why you would reach for it — it lets the lowest voice move by step where the root would have jumped.
One of Bb’s 7 common shapes does this:xx3336
All 7 common shapes as fret numbers, lowest string first. Hover or tap one to see it drawn.
How you get to it. The turn that lands on Bb 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 Bb 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).
Every note of Bb is in Bb major pentatonic, Bb major, Bb lydian, Bb mixolydian and Bb lydian dominant.
Change one note of Bb and you have Bbm (the major third becomes the minor third), Bbsus2 (the major third becomes the second), Bbsus4 (the major third becomes the fourth), Bbmaj7 (add the major seventh), Bbadd9 (add the ninth) or Bb5 (drop the major third).
Bb is a major chord — root, major third, fifth. Major chords on every root.
The common shapes and the derived voicings come from different places, and both are explained in how this site is built.
Shows each chord the way this style would voice it, and marks which of its alternatives belong to the idiom.