G Added 9th Chord

Chord Tones: G Added 9th Chord

Symbol: add9, add2 — Formula: 1-3-5-9

DegreeNoteFrequency (A=440, Equal)
1 G4 391.995 Hz
3 B4 493.883 Hz
5 D4 293.665 Hz
9 A4 440.000 Hz

Chord Notation

Notation TypeSymbol / Value
Lead Sheet SymbolGadd9
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 G4 B4 D4 A4 G G Added 9th Chord
First Inversion B4 D4 A4 G4 B G Added 9th Chord/B
Second Inversion D4 A4 G4 B4 D G Added 9th Chord/D
Third Inversion A4 G4 B4 D4 A G Added 9th Chord/A

Harmonic Function

The G add9 chord commonly functions as the dominant (V) in C major — strongest resolution point. 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 G Added 9th Chord specifically contains 4 notes: G, B, D, A (formula: 1-3-5-9). On guitar, G-rooted chords benefit from the open G, B, and D strings, enabling full-sounding voicings with minimal fretting. Country, bluegrass, and acoustic pop rely heavily on G-rooted chords, which ring with a bright, open quality on steel-string guitars.

Common Progressions

The G 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 G 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
G4 391.995 Hz 391.111 Hz 392.438 Hz
B4 493.883 Hz 495.000 Hz 490.548 Hz
D4 293.665 Hz 293.332 Hz 294.329 Hz
A4 440.000 Hz 440.000 Hz 436.043 Hz

Scales Containing the G Added 9th Chord

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