Carlos Alomar, Earl Slick, Adrian Belew, Robert Fripp, Mick Ronson etc. Bowie knew how to pick guitarists.
If you get the chance there's a doco out there called "Five Years: the making of an icon". I'm sure it'll be on tv somewhere in the next week or so. Watch it.
'As long as there's, you know, sex and drugs, I can do without the rock and roll.'