B♭ 7♭5♯9
Also known as A♯ 7♭5♯9
Same keys, different spelling.
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Listen plays the chord. Play Along lights up each note in order so you can follow.
B♭7♭5♯9
B♭ – D – F♭ – A♭ – C♯
Formula:R-M3-d5-m7-A9
Intervals:P1-M3-d5-m7-A9
Scale Degrees:1-3-b5-b7-#9
Introduction
The B♭ 7♭5♯9 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 augmented ninth.
Notes
Key Signature
The key of Bb 7♭5♯9 has 2 flats.
B♭E♭
Order of flats
Flats are added in a fixed order — the reverse of the sharp order. Each new flat key adds the next flat on the list.
B♭E♭A♭D♭G♭C♭F♭
Mnemonic: Battle Ends And Down Goes Charles’ Father
Chords in the Key of B♭ Major
These are the diatonic triads built on each degree of the B♭ major scale:
C
D
E
F
G
A
B
C
D
E
F
G
A
B
I — B♭ Major (major)
Theory: Intervals
Formula: R-M3-d5-m7-A9
Intervals: P1-M3-d5-m7-A9
The B♭ 7♭5♯9 is built by stacking intervals from the root note. The formula R-M3-d5-m7-A9 describes the scale degrees used. The intervals P1-M3-d5-m7-A9 show the distance between each note in the chord.
B♭ 7♭5♯9 — Frequently Asked Questions
What notes are in the Bb 7♭5♯9 chord?
The Bb 7♭5♯9 chord (Bb7♭5♯9) contains 5 notes: Bb, D, E, Ab, C#. Formula: R-M3-d5-m7-A9.
How is Bb7♭5♯9 used in music?
Bb7♭5♯9 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 Bb7♭5♯9?
Bb7♭5♯9 uses scale degrees 1-3-b5-b7-#9, giving it its distinctive sound.
Practice Tips
- Start by placing your thumb on Bb and spacing remaining fingers across the chord.
- Practice Bb7♭5♯9 slowly with separate hands before combining.
- Listen carefully to the tension created by the altered tones in this chord.
- Try voicing Bb7♭5♯9 in different octaves to find the most comfortable position.
- Resolve Bb7♭5♯9 to a nearby chord to hear its function in context.
Related Tools
Chord FinderLook up any chord — see the notes, hear it, and play along.Chord DrillTimed drills to build speed and recognition across all chord types.Practice RoomPlug in a MIDI keyboard and get real-time feedback on every chord and scale.Circle of FifthsVisualize key relationships, relative minors, and key signatures.MIDI MonitorLive MIDI message stream with note names, velocity, and a scrolling staff.