Tool

The harmonic field of D♭ major

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

Triads

DegreeSymbolNotesFunction
IDD♭ · F · A♭Tonic
iiEmE♭ · G♭ · B♭Subdominant
iiiFmF · A♭ · CTonic
IVGG♭ · B♭ · D♭Subdominant
VAA♭ · C · E♭Dominant
viBmB♭ · D♭ · FTonic
vii°CdimC · E♭ · G♭Dominant

Seventh chords

DegreeSymbolNotesFunction
Imaj7Dmaj7D♭ · F · A♭ · CTonic
ii7Em7E♭ · G♭ · B♭ · D♭Subdominant
iii7Fm7F · A♭ · C · E♭Tonic
IVmaj7Gmaj7G♭ · B♭ · D♭ · FSubdominant
V7A7A♭ · C · E♭ · G♭Dominant
vi7Bm7B♭ · D♭ · F · A♭Tonic
viiø7Cm7♭5C · E♭ · G♭ · B♭Dominant

The notes are spelled in octave 4, from D♭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.