after the intro there's a one measure rest then 2x 12 bar blues pattern,
inst. break, one more verse and outro.
verse:for those who don't know the blues progression
E7(4) A7(2) E7(2) B7(2) E7(2) [for comp purposes is B7(1) A7(1)]
E7=1st 2 measyres of intro
A7=measures 5+6
B7=measures 9+10