David Gilmour played lead guitar on Paul McCartney’s “No More Lonely Nights.”
Paul McCartney plays bass on Elvis Costello’s “Veronica.”
Rock luminaries including Pete Townshend, Kenny Jones, Hank Marvin, Ray Cooper, Dave Gilmour, John Paul Jones, John Bonham, Gary Brooker, and Ronnie Lane guested on Paul McCartney’s 1979 album for two tracks: “Rockestra Theme” and “So Glad To See You Here.”
John Lennon played on and co-wrote “Fame” for David Bowie.
James Taylor and Linda Ronstadt sang backup on Neil Young’s “Heart Of Gold.”
Andrew Gold (“Lonely Boy”) played on several of Linda Ronstadt’s hits.
John Stewart had backup from most of Fleetwood Mac on his hit “Gold.”
Stevie Nicks and Tom Petty made a single together, “Stop Draggin’ My Heart Around.”
George Harrison played on several of Tom Petty’s singles during the Traveling Wilburys period.
Jeff Lynne played with and/or produced Tom Petty and George Harrison and Roy Orbison on their respective albums also around the Traveling Wilburys period.
Olivia Newton-John was backed by Jeff Lynne in Electric Light Orchestra for the songs from “Xanadu.”
Hey, this is fun!