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B Dominant 9th

Listen plays the chord. Play Along lights up each note in order so you can follow.

B
A
D♯
F♯
C♯
B Dominant 9thB · D♯ · F♯ · A · C♯
B9
B – D♯ – F♯ – A – C♯
Formula:R-M3-P5-m7-M9
Intervals:P1-M3-P5-m7-M9
Scale Degrees:1-3-5-b7-9

Introduction

The B Dominant 9th chord is a five-note chord made up of B, D♯, F♯, A, and C♯. It is built from a root, major third, perfect fifth, minor seventh, and major ninth.

Notes

Notes:B – D♯ – F♯ – A – C♯

Key Signature

The key of B Dominant 9th has 5 sharps.

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.

FCGDAEB

Mnemonic: Father Charles Goes Down And Ends Battle

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
IB Major (major)
DegreeNumeralChordQuality
1IB MajorMajor
2iiC♯ MinorMinor
3iiiD♯ MinorMinor
4IVE MajorMajor
5VF♯ MajorMajor
6viG♯ MinorMinor
7vii°A♯ DiminishedDiminished

Theory: Intervals

Formula: R-M3-P5-m7-M9
Intervals: P1-M3-P5-m7-M9

The B Dominant 9th is built by stacking intervals from the root note. The formula R-M3-P5-m7-M9 describes the scale degrees used. The intervals P1-M3-P5-m7-M9 show the distance between each note in the chord.

B Dominant 9th — Frequently Asked Questions

What notes are in the B Dominant 9th chord?
The B Dominant 9th chord (B9) contains 5 notes: B, D#, F#, A, C#. Formula: R-M3-P5-m7-M9.
How is B9 used in music?
B9 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?
B9 uses scale degrees 1-3-5-b7-9, giving it its distinctive sound.

Practice Tips

  • Start by placing your thumb on B and spacing remaining fingers across the chord.
  • Practice B9 slowly with separate hands before combining.
  • Listen carefully to the tension created by the altered tones in this chord.
  • Try voicing B9 in different octaves to find the most comfortable position.
  • Resolve B9 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.