The B 9♭5 chord is a five-note chord made up of B, D♯, F, A, and C♯. It is built from a root, major third, diminished fifth, minor seventh, and major ninth.
Construction
B 9♭5 = Root + Major 3rd + Diminished 5th + Minor 7th + Major 2nd = B · D♯ · F · A · C♯
| Note | Interval | Degree |
|---|---|---|
| B | Root | 1 |
| D♯ | Major 3rd | 3 |
| F | Diminished 5th | ♭5 |
| A | Minor 7th | ♭7 |
| C♯ | Major 2nd | 9 |
Key Signature
A chord has no key signature of its own, but the B 9♭5 is the tonic (I) chord of B Major, whose key signature has 5 sharps (F♯, C♯, G♯, D♯, A♯).
F♯C♯G♯D♯A♯
Order of sharps
Sharps are added to a key signature in a fixed order. Each new sharp key adds the next sharp on the list.
F♯C♯G♯D♯A♯E♯B♯
Mnemonic: Father Charles Goes Down And Ends Battle
Chords in the Key of B Major
These are the triads built on each degree of the B major scale:
Same Notes, Other Names
The notes B – D♯ – F – A – C♯ aren’t exclusive to this chord. Depending on which note is the bass and how the chord functions, the same pitches also spell:
B 9♭5 — Frequently Asked Questions
What is the B 9♭5 chord on piano?
The B 9♭5 chord contains the notes B – D♯ – F – A – C♯. On piano, play these notes together to sound the chord.
What notes are in the B 9♭5 chord?
The B 9♭5 chord (B9♭5) contains 5 notes: B, D#, F, A, C#. Formula: R-M3-d5-m7-M9.
How is B9♭5 used in music?
B9♭5 is used in jazz, fusion, and contemporary music to add harmonic color. It appears as a dominant or tonic chord depending on context.
What is the scale degree formula for B9♭5?
B9♭5 uses scale degrees 1-3-b5-b7-9, giving it its distinctive sound.