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 A ♭ I Tonic Diatonic B ♭ m ii Subdominant Diatonic C m iii Tonic Diatonic D ♭ IV Subdominant Diatonic E ♭ V Dominant Diatonic F m vi Tonic Diatonic G dim vii° Dominant Diatonic
Degree Symbol Notes Function I A ♭ A♭ · C · E♭ Tonic ii B ♭ m B♭ · D♭ · F Subdominant iii C m C · E♭ · G Tonic IV D ♭ D♭ · F · A♭ Subdominant V E ♭ E♭ · G · B♭ Dominant vi F m F · A♭ · C Tonic vii° G dim G · B♭ · D♭ Dominant
Seventh chords A ♭ maj7 Imaj7 Tonic Diatonic B ♭ m7 ii7 Subdominant Diatonic C m7 iii7 Tonic Diatonic D ♭ maj7 IVmaj7 Subdominant Diatonic E ♭ 7 V7 Dominant Diatonic F m7 vi7 Tonic Diatonic G m7 ♭5 viiø7 Dominant Diatonic
Degree Symbol Notes Function Imaj7 A ♭ maj7 A♭ · C · E♭ · G Tonic ii7 B ♭ m7 B♭ · D♭ · F · A♭ Subdominant iii7 C m7 C · E♭ · G · B♭ Tonic IVmaj7 D ♭ maj7 D♭ · F · A♭ · C Subdominant V7 E ♭ 7 E♭ · G · B♭ · D♭ Dominant vi7 F m7 F · A♭ · C · E♭ Tonic viiø7 G m7 ♭5 G · B♭ · D♭ · F Dominant
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.
Related keys F minor Relative: the same key signature, in the other mode. A♭ minor Parallel: the same tonic, in the other mode. A♭ in the dictionary The tonic triad: notes, staff, keyboard and guitar shapes. Read about Diatonic harmony The chords that arise from stacking thirds on each degree of a scale, and why each quality lands where it does. Harmonic function The role each degree plays — tonic, subdominant, or dominant — and the tension that moves one to the next. Roman numeral analysis The notation that describes a chord by the position it occupies in the key rather than by the note it sits on. Minor key harmony The minor harmonic field, which is not one field: the three minor scales produce different chords on the same degree. 
