This harmonically sophisticated 12-bar Blues variation combines many of the ideas we have already studied–creating lots of harmonic interest and sense of forward motion…

This commonly used 12-bar Blues variation inserts a secondary dominant A7 (V7/ii) in bar 8 to feed the Dm7 (ii7) in bar 9…

This commonly used 12 bar Blues variation substitutes a ii7-V7 progression for the V7 chord in bars 9 and 10…

This commonly used 12-bar Blues variation inserts the V chord in bar 12 in order to create harmonic tension that sets up the next chorus…

A commonly used variation substitutes a IV7 chord in bar 2…

This variation creates harmonic motion by inserting an F7 chord in bar 10…