What you need: A piano and two people, one who can play a bass blues riff (pattern), and one who can play blues scales in C, F, and G.
What you do: The “bass” player plays a 5th, 6th, 7th, 6th swing pattern in the following 12-bar blues structure: (key of C) C C C C F F C C G F C C . The “treble” player plays any combination of notes in the blues scale, observing the same 12-bar chord progressions. Have fun—jam out!!