I7–IV7 in A♭ Major
Pattern: I7 – IV7
Chords: A♭7 – D♭7
Chord Breakdown
| Numeral | Chord | Type | Function |
|---|---|---|---|
| I7 | A♭7 (details) | dominant seventh | Tonic |
| IV7 | D♭7 (details) | dominant seventh | Subdominant |
Harmonic Analysis
This progression moves through A♭7 (Tonic) → D♭7 (Subdominant).
The most stripped-down blues movement: two dominant seventh chords rocking back and forth. This raw, minimal approach is the foundation of many one-chord and two-chord blues vamps.
Song Examples
- Rollin' and Tumblin' — Muddy Waters
- Crawling King Snake — John Lee Hooker