Watch the Slow Greasy online guitar lesson by Oz Noy from Twisted Guitar: Blues Soloing
This is a tune called "Slow Greasy". The groove is basically a really, really slow Texas shuffle - a "flat tire" groove. I like these kinds of tunes, because it gives you a lot of space but you still have a nice shuffle rhythm.
In terms of the changes, it's basically a 12-bar blues in Bb, but because it's slow, there's a hint of jazz in the changes.