Tool
The harmonic field of G♭ major 6 flats in the key signature. Click a degree to hear it, or hear the whole field.
Triads G ♭ I Tonic Diatonic A ♭ m ii Subdominant Diatonic B ♭ m iii Tonic Diatonic C ♭ IV Subdominant Diatonic D ♭ V Dominant Diatonic E ♭ m vi Tonic Diatonic F dim vii° Dominant Diatonic
Degree Symbol Notes Function I G ♭ G♭ · B♭ · D♭ Tonic ii A ♭ m A♭ · C♭ · E♭ Subdominant iii B ♭ m B♭ · D♭ · F Tonic IV C ♭ C♭ · E♭ · G♭ Subdominant V D ♭ D♭ · F · A♭ Dominant vi E ♭ m E♭ · G♭ · B♭ Tonic vii° F dim F · A♭ · C♭ Dominant
Seventh chords G ♭ maj7 Imaj7 Tonic Diatonic A ♭ m7 ii7 Subdominant Diatonic B ♭ m7 iii7 Tonic Diatonic C ♭ maj7 IVmaj7 Subdominant Diatonic D ♭ 7 V7 Dominant Diatonic E ♭ m7 vi7 Tonic Diatonic F m7 ♭5 viiø7 Dominant Diatonic
Degree Symbol Notes Function Imaj7 G ♭ maj7 G♭ · B♭ · D♭ · F Tonic ii7 A ♭ m7 A♭ · C♭ · E♭ · G♭ Subdominant iii7 B ♭ m7 B♭ · D♭ · F · A♭ Tonic IVmaj7 C ♭ maj7 C♭ · E♭ · G♭ · B♭ Subdominant V7 D ♭ 7 D♭ · F · A♭ · C♭ Dominant vi7 E ♭ m7 E♭ · G♭ · B♭ · D♭ Tonic viiø7 F m7 ♭5 F · A♭ · C♭ · E♭ Dominant
The notes are spelled in octave 4, from G♭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 E♭ minor Relative: the same key signature, in the other mode. F♯ minor Parallel: the same tonic, in the other mode. G♭ 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. 
