Welcome to the first and most important lesson in Major Blues 12-Bar Form & Harmony…
Within each 12-bar chorus, there are three 4-bar sub-phrases…
Phrase #1 presents the main rhythmic/melodic theme and establishes a clear sense of tonic harmony (I)…
Phrase #2 is typically a variation of or complement to the main theme played over a temporary IV harmony, with a return back to the tonic I.
Phrase #3 typically complements or answers the first two phrases and leads the listener back to the top of the next chorus. It is played over a temporary V harmony with a return to the tonic I.
Now let’s put all three phrases together…
The deep appreciation of this three-phase structure is absolutely essential to playing major 12-bar blues in authentic style. Think of 12-bar blues form as a three-line poem and you are off to a great start!