As part of this week's Lick of The Week, I've had a good harmonic look/analysis at some more "obscure" blues tunes. One entitled "Blue Comedy" by Michael Gibbs (courtesy of a reader) is right out there!
Also look at Parkers "Blues for Alice" and Coltrane's "Some Other Blues".
They demonstrate some great devices including related II's, sub V's (tritone subs) and modal interchange. I've got mp3's and pdf's on the page.
(Some licks to try also of course.)
As always, appreciate any feedback.http://pigletmusic.com/jazz-lick-week/