I've taken my accordions (both the Cajun box and a piano-key) to blues jams. One of the tunes I usually suggest to the blues-types to play is The Back Door because it is a straight 12-bar blues tune (I play it in G on my C Cajun box) and the blues folks don't have any problems playing it.

D.L. Menard said he took it from Hank Williams' Honky Tonk Blues. Link above to the English lyrics.

i think if you play it right,
there is a 2-extra-beat section between
the a and b parts..

wle.