"We Love You" (1967)
Recorded by: The Rolling Stones
Famous backups: John Lennon and Paul McCartney
After their 1967 drug bust, Mick Jagger and Keith Richards received an outpouring of support from fellow musicians, and when the Stones re-entered the studio to record their next single—the sarcastic kiss-off to establishment "We Love You" —Lennon and McCartney showed up to provide backing vocals. Just days later, the Beatles recorded the more earnest "All You Need Is Love"—on which Jagger and Richards sing backup.
"It’s Only Rock and Roll" (1974)
Recorded by: The Rolling Stones
Famous backup: David Bowie
"It's Only Rock and Roll" came together at a party at Ronnie Wood's house. In fact, it's pretty much a demo (with later overdubs) recorded in Wood's basement with whoever was around. The only Stone on the original recording is Mick Jagger (Ronnie wasn't in the band yet). Luckily, the guest list also included Bowie, who sings backup on the chorus.
"Fame" (1975)
Recorded by: David Bowie
Famous Backup: John Lennon
At the time, Lennon was approaching the end of his "lost weekend" (separated from Yoko, spending countless nights in L.A. drinking with Harry Nilsson). But he found time for side projects—like co-writing Bowie's No. 1 hit "Fame." Lennon also provided backing vocals and guitar on the track.
"Heart of Gold" and "Old Man" (1972)
Recorded by: Neil Young
Famous backups: Linda Ronstadt and James Taylor
After they all appeared on the same episode of "The Johnny Cash Show," Young invited Ronstadt and Taylor to guest on a couple of tracks—"Old Man" and "Heart of Gold"—he was recording for his album "Harvest."
"You’ve Lost That Lovin’ Feelin'" (1964)
Recorded by: The Righteous Brothers
Famous backup: Cher 
Before she and Sonny topped the charts with "I Got You Babe," Cher worked for producer Phil Spector, singing backup on many of his "Wall of Sound" singles, including the Righteous Brothers' chart-topper "You've Lost That Lovin' Feelin'."
"Doctor My Eyes" (1972)
Recorded by: Jackson Browne
Famous backup: David Crosby and Graham Nash
Vocal blending came naturally to Crosby, Stills & Nash, so it's no surprise that David Crosby and Graham Nash appear as backup vocalists on many classic tunes. One of their greatest cameos is on Browne's surprise hit "Doctor My Eyes." Listen for the CSN-style harmonies during the chorus.
"The Bitch Is Back" (1974)
Famous backup: Dusty Springfield
She belongs in the spotlight. (Seriously, how do you hear this and not immediately make her the lead vocal?) Still, Springfield's mid-'70s backup gig must have been fun. After all, nobody can have a bad time while singing Elton John's "The Bitch Is Back."
"While My Guitar Gently Weeps" (1968)
Recorded by: The Beatles
Famous backup: Eric Clapton
During the difficult "White Album" sessions, George Harrison brought along his pal Clapton to a) break the mounting tension within the band, and b) add his signature blues sting to "While My Guitar Gently Weeps." The celebrated Cream guitarist wailed through two solos that sound like nothing else on a Beatles record.
"Pet Sounds" (1966)
Recorded by: The Beach Boys
Famous backup: Glen Campbell
To a large extent, the first five years of Glen Campbell's career consisted of backing up other artists as a session musician with the storied Wrecking Crew. You've likely heard his guitar on records by Elvis Presley, Nancy Sinatra, the Monkees, Ricky Nelson and Frank Sinatra. But his work with the Beach Boys really stand out. Just listen this trackfrom "Pet Sounds"—or any of them.
"You’re So Vain" (1972)
Recorded by: Carly Simon
Famous backup: Mick Jagger
Even though Jagger isn't credited, we all know about this one, partly because his voice on "You're So Vain" is instantly identifiable. In fact, on the final chorus, he and Carly Simon basically sing a duet. Between that and the early rumors (later denied) that Simon had written the song about the Stones frontman, no list of famous backups could overlook him.
"I’m Every Woman" (1978)
Recorded by: Chaka Khan
Famous backup: Whitney Houston
Early on, Houston made the rounds as a backup singer, and "I'm Every Woman" was her most famous backup gig before the release of her self-titled 1985 debut album, which sold 30 million copies. She later made the song her own on the soundtrack for "The Bodyguard,"
