12-Bar Blues (Standard)
Where does rock come from? From 12 bars and 3 dominant chords
The 12-Bar Blues is the mother structure of modern music. Sweet Home Chicago, Johnny B. Goode, Pride and Joy… all follow the same 12-bar map. Rock, blues, R&B — everything starts here.
I7I7I7I7IV7IV7I7I7V7IV7I7V7
Complete guide
Level: Intermediate Styles: Blues
🎵 A-A-B Structure
The 12-bar blues is divided into 3 phrases of 4 bars:
- Phrase 1 (Bars 1-4): Establishes the tonic (I7).
- Phrase 2 (Bars 5-8): Moves up to IV7 (tension) and returns to I7.
- Phrase 3 (Bars 9-12): The climax (V7), down to IV7, and resolution (I7).
🎹 The "Weird" Part: Major Chords with Minor 7ths
In classical music, the I chord is Maj7 (stable). In Blues, the I is Dominant (7). This creates a constant, unstable tension that is the signature blues sound.
In C:
- C7 (C-E-G-Bb) ← That Bb is the key.
- F7 (F-A-C-Eb)
- G7 (G-B-D-F)
💡 Boogie Woogie
The left-hand boogie_woogie pattern is essential. Practice it slowly.