Out of the blue I was thinking about the old tune Wooly Bully. I wanted to confirm it was a 12 bar blues. When I counted I got 15 bars. The first 1 chord is held for 7 bars, then the rest is a traditional blues pattern. I never knew. Now I want to go to a jam and say, "we're gonna do a 15 bar blues", just to mess with the other jammer's head. (gee, during this covid thing, I just wanna go to a jam, period)
Fun fact: it was reworking of Hully Gully Now by Big Bo & The Arrows, which apparently was influenced by Feelin Good by Junior Parker, which in turn was of course influenced by Boogie Chillen by JLH, who was never one for a standard number of bars
