G. He's playing basically in G. He's using an A string where his D goes, an E where his A goes and no G and a solid steel B. He tunes in what would be a G. I got an old Strat that I tune in G and remove the 6th for a five string. Gets the same effect but you can go on with out changing guitars. ( the 6th is just a redundant anyway and I don't feel like feeling around to mute it.) Comes in handy on Ry Cooder's and Kieth Richards' (same thing really) material too. Remember to go for the small amp on Steve's stuff so you can really crank the distortion up in it. One of his trademars is that raw edge.