Tool

The harmonic field of B major

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

Triads

DegreeSymbolNotesFunction
IBB · D♯ · F♯Tonic
iiCmC♯ · E · G♯Subdominant
iiiDmD♯ · F♯ · A♯Tonic
IVEE · G♯ · BSubdominant
VFF♯ · A♯ · C♯Dominant
viGmG♯ · B · D♯Tonic
vii°AdimA♯ · C♯ · EDominant

Seventh chords

DegreeSymbolNotesFunction
Imaj7Bmaj7B · D♯ · F♯ · A♯Tonic
ii7Cm7C♯ · E · G♯ · BSubdominant
iii7Dm7D♯ · F♯ · A♯ · C♯Tonic
IVmaj7Emaj7E · G♯ · B · D♯Subdominant
V7F7F♯ · A♯ · C♯ · EDominant
vi7Gm7G♯ · B · D♯ · F♯Tonic
viiø7Am7♭5A♯ · C♯ · E · G♯Dominant

The notes are spelled in octave 4, from B4. 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.