This canon, in this song.
I have listened to a number of rehearsal takes, and from that perspective I think he created that right there in the room with the musicians, rather than write something.
also see: Doreen from You Are What You Is and the unreleased Crush All Boxes. I like the version on the latter better at this time, but I don't think that track from that album is isolated on the youtube currently.
this thing
'Johnny Guitar Watson throws the f**k down on this track'