The Backdoor Progression
The backdoor progression approaches a major tonic through a flat-seven dominant chord. In C, a common version is Fm7-Bb7-Cmaj7.
- in C: Fm7-Bb7-Cmaj7
- bVII7 to I
- borrowed color
What are the chords in C?
Fm7 contains F-A flat-C-E flat. Bb7 contains B flat-D-F-A flat. Cmaj7 contains C-E-G-B. The first two bring A flat and E flat from outside C major, and Bb7 places a flat-seven root below the tonic C.
Why does Bb7 lead to C without G7?
Two Bb7 notes move by step into Cmaj7: D rises to E and A flat falls to G. The F can move to E, while B flat can move to B or C. These small voice-leading moves make the arrival smooth even though Bb7 is not the ordinary V7 of C.
Where does 'backdoor' come from?
The standard 'front door' dominant in C is G7-C. The backdoor uses Bb7-C instead, often prepared by Fm7. The label describes an alternative route to the same tonic, not a new key or a special chord type.
Is Fm7 required?
No. Bb7-C can make the essential backdoor move on its own. Adding Fm7 prepares Bb7 as a ii-V pair in E flat major, while the actual landing is C. Try the two-chord and three-chord versions with the same Cmaj7 ending and compare the amount of setup.
Keep going
Everything in chord progressions
- The Backdoor Progression
- The Progression Explorer
- How Chord Progressions Work
- Royal Road Progression