I am pretty sure he would playing a "blues harp" (harmonica) and, danelectro i think is spot on....Shook me all night long, I am pretty sure it is an "A" Harp as the song is played in "E" then "A" is the cross harp you would use for that bluesy sound. I got my "A" harp out and it was pretty bloody close to the recording, but as danelectro again being spot on, the pitches can change a slight bit with recording and subsequent copying files etc. I am only just learning to play Zep harmonica now so if anyone else has any tips etc, would be happy to hear from you. cheers Stewy "There is Led Zeppelin, then there is all other bands"