Elvis Costello joined Spinal Tap onstage on Saturday night (April 27th) at New York City's Beacon Theatre. The New York Post reported Costello took the stage with Christopher Guest, Harry Shearer, and Michael McKean during their acoustic set, which followed a screening of 1984 This Is Spinal Tap, which was shown as part of the Tribeca Film Festival. Costello, also on acoustic guitar, took the lead vocal on the Tap's Kinks-esque “British Invasion” nugget “Gimme Some Money.”

Other songs performed by the trio were “Flower People,” “Hell Hole,” “All The Way Home,” “Clam Caravan,” and “Sex Farm.” Director Rob Reiner was on hand earlier to introduce the film.

Although Elvis Costello is by far one of the most scholarly singer-songwriters when it comes to pop music in the 20th century, he understands that the actual art of songwriting is as big a mystery to him as it was to his heroes: “Music just starts to arrive in your head and at your fingertips and you don't have any choice but to — y'know, unless you're a real fool — to take it on, and try and work out what it is that is happening.”