Western theory library
Blues foundations
Start with the six-note blues scaleBlues scaleA pitch collection commonly taught for blues melody and improvisation. The common minor blues scale adds a lowered fifth to minor pentatonic.Source: TR G5 p. 23, Pitch §10; G6 p. 27, Pitch §15.More in the glossary and a standard 12-bar form. Real blues practice is broader than this template, especially in phrasing, blue-note intonation, harmony, and form.
I, IV and V mean chords whose roots are the key note, the note a perfect fourth above it and the note a perfect fifth above it: C7, F7 and G7 in C. They are counted from the key, not from the six-note blues scaleBlues scaleA pitch collection commonly taught for blues melody and improvisation. The common minor blues scale adds a lowered fifth to minor pentatonic.Source: TR G5 p. 23, Pitch §10; G6 p. 27, Pitch §15.More in the glossary shown above. Each is a dominant-seventh chord: a major chord with a note a minor seventh above its root.
C blues scaleBlues scaleA pitch collection commonly taught for blues melody and improvisation. The common minor blues scale adds a lowered fifth to minor pentatonic.Source: TR G5 p. 23, Pitch §10; G6 p. 27, Pitch §15.More in the glossary
Formula: 1 - b3 - 4 - b5 - 5 - b7
12-bar form
Bar 1 · I
C7
Bar 2 · I
C7
Bar 3 · I
C7
Bar 4 · I
C7
Bar 5 · IV
F7
Bar 6 · IV
F7
Bar 7 · I
C7
Bar 8 · I
C7
Bar 9 · V
G7
Bar 10 · IV
F7
Bar 11 · I
C7
Bar 12 · V
G7
Source notes
The form explanation follows Open University and Open Music Theory introductions to the 12-bar blues. The tool keeps the common I-IV-V dominant-seventh model visible but does not present it as the only blues form.