--Clapton, "While My Guitar Gently Weeps"
--Ronnie Wood, on the Townsend/Lane album Rough Mix
--Lindsey Buckingham's vocals on Tom Petty's "Walls"
--Ry Cooder on John Hiatt's Bring the Family
--Duane Allman on Boz Scaggs's "Loan Me a Dime"
--Utopia on Shaun Cassidy's Wasp
--Sonny Rollins on the Stones' "Waiting On a Friend"
--Alex Chilton on Chris Bell's "You and Your Sister"
--Adrian Belew on Remain in Light
--Stevie Nicks on Tom Petty's "Stop Draggin' My Heart Around" (I know its
the other way around release-wise, but this is Nicks singing over a
Heartbreakers track)