Tool

The harmonic field of A♭ major

4 flats in the key signature. Click a degree to hear it, or hear the whole field.

Triads

DegreeSymbolNotesFunction
IAA♭ · C · E♭Tonic
iiBmB♭ · D♭ · FSubdominant
iiiCmC · E♭ · GTonic
IVDD♭ · F · A♭Subdominant
VEE♭ · G · B♭Dominant
viFmF · A♭ · CTonic
vii°GdimG · B♭ · D♭Dominant

Seventh chords

DegreeSymbolNotesFunction
Imaj7Amaj7A♭ · C · E♭ · GTonic
ii7Bm7B♭ · D♭ · F · A♭Subdominant
iii7Cm7C · E♭ · G · B♭Tonic
IVmaj7Dmaj7D♭ · F · A♭ · CSubdominant
V7E7E♭ · G · B♭ · D♭Dominant
vi7Fm7F · A♭ · C · E♭Tonic
viiø7Gm7♭5G · B♭ · D♭ · FDominant

The notes are spelled in octave 4, from A♭4. The function is assigned by degree — tonic on I, III and VI; subdominant on II and IV; dominant on V and VII — which is how the harmonic field is taught. Context can change that reading, and the tool reports the degree.