Concertgoers at Paul Simon’s Friday show at New York’s Beacon Theater were in for a very pleasant surprise when the other half of the Simon & Garfunkel duo took the stage for a brief, but lively performance.

Singing at the reopening of the legendary Beacon Theater on the Upper East Side, Paul Simon put on an impressive 90-minute show, completed with a three-song performance alongside Art Garfunkel, who joined him on stage for “The Sound of Silence,” “The Boxer” and “Old Friends,” in what is believed to be just their third appearance together since their 2004 reunion tour.

“The fact that you still care is tremendous,” said Garfunkel during the crowd’s standing ovation following “The Sounds of Silence.” Garfunkel had flown in from Florida, where he played in Key Largo the night before, and he returned to play in Fort Pierce the next night.

The two dueted in front of a star-studded audience which included Paul McCartney (and Nancy Shevell), Jon Bon Jovi with wife Dorothea, Harvey Weinstein and Georgina Chapman, Rosie O’Donnell and Kelli Carpenter, Whoopi Goldberg, James Gandolfini, musician Robert Randolph, and Jimmy Fallon with wife Nancy Juvnonen, as well as Mayor Michael Bloomberg.

Although billed just as a Paul Simon show, the musician received some help from members of the cast of his late lamented Broadway show, The Capeman, who joined him for several numbers. He played for over two hours with a 20-minute intermission and covered all parts of his solo career, from “You Can Call Me Al,” “Graceland,” and “Boy in the Bubble” to earlier hits, like ”Me and Julio,” “Loves Me Like A Rock,” “Late in the Evening,” and “Slip Slidin’ Away.”