Variations on Twelve Bars

The twelve-bar form you learned is a skeleton, and bands vary it constantly without announcing that they have.

The most common variation is the quick change: instead of four bars of I at the top, bar two goes to the IV and comes straight back. Whether a band plays the quick change or not is decided in the first two bars of the first chorus, and if you guess wrong everybody hears it.

Stop time is the other one you must recognise. The band plays a stab on beat one and then silence, leaving the soloist alone for the rest of the bar. It usually happens at the top of a chorus and it is devastating if you are not ready and glorious if you are.

There is also the slow blues in twelve-eight, which lesson nine covers, and the eight-bar blues, which drops bars rather than adding them.

The practical skill is listening to the first chorus before you play anything. Sit out the first twelve bars of any jam and you will know which blues you are in.

E7

E7, open. This lesson's track is an acoustic blues, where open dominant shapes are the idiom rather than a compromise.

A7

A7 — the IV chord, and the one that appears early if the band plays a quick change.

B7

B7, the V.

This track is an acoustic blues in E.

Sit out the entire first chorus and just listen. Does bar two stay on E or move to A? Count it and find out before you play a note.

Then play the form as you heard it, not as you expected it. That habit — listening first, matching what is actually happening — is most of what separates a player people call back from one they do not.

An acoustic blues in E. Sit out the first chorus and work out which variation it uses.