D Added 9th Chord

Chord Tones: D Added 9th Chord

Symbol: add9, add2 — Formula: 1-3-5-9

DegreeNoteFrequency (A=440, Equal)
1 D 293.665 Hz
3 F# 369.994 Hz
5 A 440.000 Hz
9 E 329.628 Hz

Chord Notation

Notation TypeSymbol / Value
Lead Sheet SymbolDadd9
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 D F# A E D D Added 9th Chord
First Inversion F# A E D F# D Added 9th Chord/F#
Second Inversion A E D F# A D Added 9th Chord/A
Third Inversion E D F# A E D Added 9th Chord/E

Harmonic Function

The D add9 chord commonly functions as the supertonic (ii) in C major or dominant (V) in G 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 D 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 D 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
D 293.665 Hz 293.332 Hz 294.329 Hz
F# 369.994 Hz 371.251 Hz 367.911 Hz
A 440.000 Hz 440.000 Hz 436.043 Hz
E 329.628 Hz 330.001 Hz 327.032 Hz

Scales Containing the D Added 9th Chord

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