B Added 9th Chord

Chord Tones: B Added 9th Chord

Symbol: add9, add2 — Formula: 1-3-5-9

DegreeNoteFrequency (A=440, Equal)
1 B 493.883 Hz
3 D# 311.127 Hz
5 F# 369.994 Hz
9 C# 277.183 Hz

Chord Notation

Notation TypeSymbol / Value
Lead Sheet SymbolBadd9
All Common Symbolsadd9, add2
Interval Formula1-3-5-9
Harmonic Categorybright

Roman numeral (e.g. I, IV, V) and Nashville Number notation are key-dependent. See Keys pages for chord function within specific keys.

Inversions

InversionNotes (low to high)Bass NoteSlash Notation
Root Position B D# F# C# B B Added 9th Chord
First Inversion D# F# C# B D# B Added 9th Chord/D#
Second Inversion F# C# B D# F# B Added 9th Chord/F#
Third Inversion C# B D# F# C# B Added 9th Chord/C#

Harmonic Function

The B add9 chord commonly functions as the leading tone (vii) in C major or dominant (V) in E major. Its harmonic role varies by key — in major keys it provides stable harmonic grounding.

The add9 chord adds a ninth (octave + second) to a major triad without including the seventh. It has a bright, open sound, richer than a plain major chord but less complex than a major ninth.

Common Progressions

The B Added 9th Chord frequently appears in these progression patterns (shown in Roman numeral notation relative to key):

Songs Featuring the Added 9th Chord

Well-known songs where the B Added 9th Chord — or this chord type — plays a prominent role:

Tuning Frequencies Across Temperaments

Frequencies shown at A=440 Hz. View full temperament data for any note.

NoteEqual Temp.PythagoreanJust Intonation
B 493.883 Hz 495.000 Hz 490.548 Hz
D# 311.127 Hz 309.026 Hz 313.951 Hz
F# 369.994 Hz 371.251 Hz 367.911 Hz
C# 277.183 Hz 278.437 Hz 279.067 Hz

Scales Containing the B Added 9th Chord

These scales include the B Added 9th Chord as a diatonic or characteristic chord: