Spinal Tap reference aside, I'm actually getting a little more obscure on this tune than usual. There is a fantastic bootleg of Cream from 1966 from a club called Klooks Kleek where the band is amazing and Clapton is at the peak of his youth angst ridden powers, playing a Gibson into a cranked Marshall stack. There's nothing better than that on the planet.
They do a cool version Howlin' Wolf's "Meet Me in the Bottom" that I've always loved and wanted to share. The bootleg is extremely easy to find online (like just about everything else). Just google Cream and Klooks Kleek and enjoy! Man they were good, and this was in 1966!