The key of E♭ major
E♭ F G A♭ B♭ C D
3 flats: B♭ E♭ A♭. Relative minor: The key of C minor.
The triads of the key
I
E♭ | ii
Fm | iii
Gm | IV
A♭ | V
B♭ | vi
Cm | vii°
D° |
The seventh chords
Imaj7
E♭maj7 | ii7
Fm7 | iii7
Gm7 | IVmaj7
A♭maj7 | V7
B♭7 | vi7
Cm7 | viiø7
Dm7♭5 |
E♭ major scale
Open it in the app: 6. Harmony, in E♭