The Rolling Stones welcomed pop star Katy Perry onstage during their Saturday night (May 11th) appearance at Las Vegas’ MGM Grand Garden Arena. Perry — who was still a year away from being born when the Stones released 1983’s Undercover collection — duetted with Mick Jagger on the 1978 Some Girls classic, “Beast Of Burden.” Perry joins a growing cast of cameo players sitting in on the Stones’ 2013 50 & Counting dates, which now include Gwen Stefani, Keith Urban, Tom Waits, John Fogerty, and Bonnie Raitt. Once again Mick Taylor, in addition to his star turn during “Midnight Rambler,” joined the band for the final encore of “(I Can’t Get No) Satisfaction.”

Also appearing in Saturday night’s setlist was the Exile On Main Street rocker, “All Down The Line,” the Voodoo Lounge favorite “You’ve Got Me Rocking,” and the Green Valley High School Choir guesting on “You Can’t Always Get What You Want.”

• With an such a deep and rich back catalogue, we asked Keith Richards how in rehearsal the band consolidates the decades into one two-and a-half hour setlist: