Tool
The harmonic field of C♭ major 7 flats in the key signature. Click a degree to hear it, or hear the whole field.
Triads C ♭ I Tonic Diatonic D ♭ m ii Subdominant Diatonic E ♭ m iii Tonic Diatonic F ♭ IV Subdominant Diatonic G ♭ V Dominant Diatonic A ♭ m vi Tonic Diatonic B ♭ dim vii° Dominant Diatonic
Degree Symbol Notes Function I C ♭ C♭ · E♭ · G♭ Tonic ii D ♭ m D♭ · F♭ · A♭ Subdominant iii E ♭ m E♭ · G♭ · B♭ Tonic IV F ♭ F♭ · A♭ · C♭ Subdominant V G ♭ G♭ · B♭ · D♭ Dominant vi A ♭ m A♭ · C♭ · E♭ Tonic vii° B ♭ dim B♭ · D♭ · F♭ Dominant
Seventh chords C ♭ maj7 Imaj7 Tonic Diatonic D ♭ m7 ii7 Subdominant Diatonic E ♭ m7 iii7 Tonic Diatonic F ♭ maj7 IVmaj7 Subdominant Diatonic G ♭ 7 V7 Dominant Diatonic A ♭ m7 vi7 Tonic Diatonic B ♭ m7 ♭5 viiø7 Dominant Diatonic
Degree Symbol Notes Function Imaj7 C ♭ maj7 C♭ · E♭ · G♭ · B♭ Tonic ii7 D ♭ m7 D♭ · F♭ · A♭ · C♭ Subdominant iii7 E ♭ m7 E♭ · G♭ · B♭ · D♭ Tonic IVmaj7 F ♭ maj7 F♭ · A♭ · C♭ · E♭ Subdominant V7 G ♭ 7 G♭ · B♭ · D♭ · F♭ Dominant vi7 A ♭ m7 A♭ · C♭ · E♭ · G♭ Tonic viiø7 B ♭ m7 ♭5 B♭ · D♭ · F♭ · A♭ Dominant
The notes are spelled in octave 4, from C♭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 A♭ minor Relative: the same key signature, in the other mode. B minor Parallel: the same tonic, in the other mode. C♭ 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. 
