Watch the Grantalope online guitar lesson by David Hamburger from 50 Jazz-Blues Licks You MUST Know
It may seem like jazz musicians are continually trying to pull the rug out from underneath you with their tricky chord changes - why can’t they just play I, IV and V, like everyone else? - but a little level-headed observation tends to reveal that, at least when it comes to the blues, there are really just a handful of paths through those twelve bars.
Case in point: on a minor blues, jazzers reach for either the minor iv chord or the bVI chord in bars 5 and 6. It’s pretty much one or the other, and with a little practice you’ll hear it just as quickly as you can hear whether Albert Collins is going to the quick IV in measure 2 or not on a Texas shuffle. Likewise, the turnaround in the last four bars of a minor blues usually only goes in one of a couple of pretty recognizable directions. The default is arguably bVI to V to i, which in the key of, say, G minor, means going from Eb7 to D7 to G minor (if you played it in the same key, "The Thrill is Gone" would have a turnaround from Ebmaj7 to D7 to Gmin, which is pretty similar).
What’s good to know is that most deviations from this one turnaround tend to just be elaborations on a framework: swapping in Eb9 for Eb7, adding b9, #9 and/or b13 alterations to the V chord, and sneaking in a iimin7b5 chord between bVI and V. Do all of those at once in the key of G minor and you get: Eb9 to Amin7b5 to D7alt. to Gmin. Cool? Now all you gotta do is play over it.