Bb7 piano chord, Bb dominant 7th notes and fingering.

The Bb7 piano chord is Bb dominant 7th: Bb, D, F and Ab. It is the Bb major triad (Bb, D, F) with a minor seventh (Ab) added on top, ten semitones above the root. A plain 7 in a chord name, as in Bb7, always means this flat seventh, not the major seventh.

How to play Bb7 on piano

1. Find Bb on the keyboard. Bb is the third black key of the group of three, just before B. It is the same key as A#.
2. With your right hand, put finger 1 on Bb, finger 2 on D, finger 3 on F and finger 5 on Ab. Finger 1 is the thumb.
3. Press all four keys together. In root position they run from Bb3 to Ab4, a reach of 10 semitones. Play chord sounds them together and Arpeggio sounds them one by one, from the bottom up.
4. Click Left hand to see the left hand. It plays Bb2 to Ab3, one octave lower: Bb with finger 5, D with finger 3, F with finger 2, Ab with finger 1.
5. The cards under the keyboard hold the four positions, with Bb, D, F and Ab at the bottom in turn. Play and Arpeggio on a card play that position.
6. Open Note names. As written the keys read Bb, D, F and Ab. Sharps shows A#, D, F and G#, and Flats shows Bb, D, F and Ab. This chord is written with flats, so As written and Flats match.

How Bb7 is built

Counted from the root, the formula is 0, 4, 7, 10. Stacked on each other the gaps are 4 + 3 + 3: a major third, a minor third and another minor third. The third (D) and the seventh (Ab) are 6 semitones apart, which is a tritone, the most tense interval in the chord. That pair is what makes the chord lean toward a resolution.

Worked example: the pitch of Bb3. On a piano tuned to A4 = 440 Hz, a note 11 semitones below A4 has the frequency 440 × 2^(-11/12), which is about 233.08 Hz. D4 is 7 semitones below A4, so 440 × 2^(-7/12) gives about 293.66 Hz.

Bb7 and A#7 are the same chord on the keyboard: the same four keys sound for both. Written as A#7 it would need a double accidental (A#, C##, E# and G#), so Bb is the name that sheet music uses. The key of Bb major has 2 flats, while the key of A# major would need double accidentals.

What the keys look like under your hand

The white keys beside Bb are A on the left and B on the right, a semitone each way. Two of the four notes are black keys (Bb and Ab) and two are white keys (D and F). Your thumb lands on Bb, a black key with A and B beside it. Keep the thumb relaxed and slightly curved, and let the wrist stay level instead of twisting to reach. Your little finger plays Ab, a black key with G and A beside it. The little finger is short, so let the hand lean a little toward its edge and aim for the middle of the key.

Bb7 inversions and fingering

Bb7 has four positions. In root position Bb is at the bottom. In the first inversion, D is at the bottom and the chord is written Bb7/D. In the second inversion, F is at the bottom and the chord is written Bb7/F. In the third inversion, Ab is at the bottom and the chord is written Bb7/Ab. The tightest reach, 8 semitones from the lowest key to the highest, is the first inversion. The widest, at 10, is the root position.

The keys that hold Bb7

Bb7 fits two of the major and natural minor keys that have a standard key signature, which means every note of it comes from that key's scale. The simplest is Eb major, with 3 flats, where it is chord V7.

Progressions that use Bb7, with the chord numbers and the chords in that key:

• Eb major: Imaj7-IVmaj7-V7-Imaj7, which is Ebmaj7, Abmaj7, Bb7, Ebmaj7, the three-chord cadence of folk, rock and blues.
• C minor: i7-VII7-VImaj7-VII7, which is Cm7, Bb7, Abmaj7, Bb7, a rocking figure between VII and VI.
• Eb major: vi7-IVmaj7-Imaj7-V7, which is Cm7, Abmaj7, Ebmaj7, Bb7, the four-chord loop started from the vi chord.

Blues: a 12-bar blues in Bb is built on Bb7, Eb7 and F7.

Here is a worked example in Eb major. The chord before Bb7 in the first progression above is Abmaj7 (Ab, C, Eb and G). From Abmaj7 in root position, the closest way to reach Bb7 is its third inversion (Ab, Bb, D and F, lowest note first): one note stays where it is, and the others move 5 semitones in total, counting each note against the note in the same place from the bottom.

Look at the top three notes of Bb7: D, F and Ab make a D diminished chord (D, F and Ab). A dominant 7th is a diminished triad with the root added underneath.

What Bb7 sounds like

The dominant 7th is restless. Its tritone between D and Ab pulls toward a resolution, and the chord most naturally moves to Eb, a fifth below Bb. It is the sound of the blues too, where every chord can be a dominant 7th.

Here Bb7 is the V7 chord in Eb major and the VII7 chord in C minor. In a 12-bar blues in Bb the three chords are Bb7, Eb7 and F7. In minor keys the same chord appears as V7 of Eb minor, using the raised seventh of the harmonic minor scale.

A common mistake with Bb7

A common mistake is pressing A instead of Ab on top, one semitone higher than the seventh of Bb7. That gives Bbmaj7 (Bb, D, F and A), which sounds soft where Bb7 sounds restless. Check the top note: it should be the lower of the two keys.

Chords to learn next

Chords close to Bb7: Bb major (the same chord without the seventh; shares Bb, D and F); Bbmaj7 (a major seventh instead; shares Bb, D and F); Bbm7 (a minor third instead; shares Bb, F and Ab); Eb major (the chord it leads to; shares Bb).

Once Bb7 feels easy, play it and then Eb major to hear the chord resolve. For chords beyond these six types, and for guitar and ukulele shapes, use the chord finder. To play along with your computer keys, open the virtual piano. The piano chords page lists all 72 chords.