Tool

The harmonic field of G major

1 sharp in the key signature. Click a degree to hear it, or hear the whole field.

Triads

DegreeSymbolNotesFunction
IGG · B · DTonic
iiAmA · C · ESubdominant
iiiBmB · D · F♯Tonic
IVCC · E · GSubdominant
VDD · F♯ · ADominant
viEmE · G · BTonic
vii°FdimF♯ · A · CDominant

Seventh chords

DegreeSymbolNotesFunction
Imaj7Gmaj7G · B · D · F♯Tonic
ii7Am7A · C · E · GSubdominant
iii7Bm7B · D · F♯ · ATonic
IVmaj7Cmaj7C · E · G · BSubdominant
V7D7D · F♯ · A · CDominant
vi7Em7E · G · B · DTonic
viiø7Fm7♭5F♯ · A · C · EDominant

The notes are spelled in octave 4, from G4. 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.