A 35th anniversary showing of This Is Spinal Tap screened at the Beacon Theatre for NYC’s Tribeca Film Festival on Saturday. Following the film, there was a Q&A with director/actor Rob Reiner as well as the other members from the fictional band, Christoper Guest, Michael McKean, and Harry Shearer.

If that wasn’t enough for fans, the three band members picked up acoustic guitars and showed the crowd that they’ve still got it by performing songs from the film live onstage. Before one of the songs, “Gimme Some Money,” surprise guest Elvis Costello joined the group onstage to perform lead vocals. Watch footage of that moment below.

Shearer’s Spinal Tap character Derek Smalls released a star-studded solo album last year, while Costello and the Attractions just released their Purse EP as a Record Store Day exclusive.