B Added 9th Chord

Chord Tones: B Added 9th Chord

Symbol: add9, add2 — Formula: 1-3-5-9

DegreeNoteFrequency (A=440, Equal)
1 B4 493.883 Hz
3 D♯4 311.127 Hz
5 F♯4 369.994 Hz
9 C♯4 277.183 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 B4 D♯4 F♯4 C♯4 B B Added 9th Chord
First Inversion D♯4 F♯4 C♯4 B4 D♯ B Added 9th Chord/D♯
Second Inversion F♯4 C♯4 B4 D♯4 F♯ B Added 9th Chord/F♯
Third Inversion C♯4 B4 D♯4 F♯4 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. The B Added 9th Chord specifically contains 4 notes: B, D♯, F♯, C♯ (formula: 1-3-5-9). On guitar, B-rooted chords are typically played as barre chords at the second or seventh fret, and on piano they use a comfortable mix of black and white keys. K-pop, J-pop, and modern R&B productions frequently feature B-rooted chords, chosen for how the key sits within typical vocal ranges.

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
B4 493.883 Hz 495.000 Hz 490.548 Hz
D♯4 311.127 Hz 309.026 Hz 313.951 Hz
F♯4 369.994 Hz 371.251 Hz 367.911 Hz
C♯4 277.183 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: