This one is called "Lovin' You" and it's based on the chord progression for Led Zeppelin's "Since I've Been Loving You." This is a 12 bar blues with some nice alternate changes that you do have to be careful with since they are distinctly Led Zeppelin. In fact, I can't think of another song that uses these changes, so bravo Jimmy Page!
I really wanted to share this tune with you as it's one of my favorite songs by them, and one of my favorite blues chord progressions. For years I didn't know how to play the chords correctly, and have seen many people get them wrong so I wanted to set the record straight. I highly suggest picking up Led Zeppelin III and listening to the original. Play along with it and try to pick up some of the cool riffs that Jimmy adds to this classic chord progression.