I've been yelling about Tina Brooks for the past few weeks, so I thought it was time to (A) figure out a few of his licks myself and (B) show you what I'm talking about. So here's a short lick that will take you from the I chord to the IV chord, inspired by one of Brooks' moves in the first chorus of the blues "Back To The Tracks." I've included some tab and notation as well, to show you what's happening.

The basic idea is, in bar three of a 12-bar blues, you begin to think: "Ok, we're headed towards an Eb chord. I know Eb is the IV in the key of Bb. But, just supposing Eb was a I chord – what would its V chord be? Ah, Bb. And we could make that a Bb7altered sound if we wanted to, by adding the b13 and the b9. And what would the ii of Eb be? Fmin7, which we could also play as an Fmin9."

So that's how you get licks like this one: by (1) approaching the Eb with its own ii-V resolution, to get Fmin to Bb7 to Eb, (2) dressing up the Fmin and Bb7 chords with some upper extensions,...