B♭ 7♭9♯11
Also known as A♯ 7♭9♯11
Same keys, different spelling.
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B♭7♭9♯11
B♭ – D – F – A♭ – C♭ – E
Formula:R-M3-P5-m7-m9-A11
Intervals:P1-M3-P5-m7-m9-A11
Scale Degrees:1-3-5-b7-b9-#11
Introduction
The B♭ 7♭9♯11 chord is a six-note chord made up of B♭, D, F, A♭, C♭, and E. It is built from a root, major third, perfect fifth, minor seventh, minor ninth, and augmented eleventh.
Notes
Key Signature
The key of Bb 7♭9♯11 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-P5-m7-m9-A11
Intervals: P1-M3-P5-m7-m9-A11
The B♭ 7♭9♯11 is built by stacking intervals from the root note. The formula R-M3-P5-m7-m9-A11 describes the scale degrees used. The intervals P1-M3-P5-m7-m9-A11 show the distance between each note in the chord.
B♭ 7♭9♯11 — Frequently Asked Questions
What notes are in the Bb 7♭9♯11 chord?
The Bb 7♭9♯11 chord (Bb7♭9♯11) contains 6 notes: Bb, D, F, Ab, B, E. Formula: R-M3-P5-m7-m9-A11.
How is Bb7♭9♯11 used in music?
Bb7♭9♯11 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♭9♯11?
Bb7♭9♯11 uses scale degrees 1-3-5-b7-b9-#11, giving it its distinctive sound.
Practice Tips
- Start by placing your thumb on Bb and spacing remaining fingers across the chord.
- Practice Bb7♭9♯11 slowly with separate hands before combining.
- Listen carefully to the tension created by the altered tones in this chord.
- Try voicing Bb7♭9♯11 in different octaves to find the most comfortable position.
- Resolve Bb7♭9♯11 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.