U2 may have sold out hundreds of arenas and sold thousands of albums, but that didn’t stop the band from performing on a New York City subway platform.

The multi-platinum rock group surprised travelers by acting as street performers in Grand Central’s subway station by the 42nd Street S shuttle on May 4, where they sang their song “Angel of Harlem.”

Among the excited spectators was Jimmy Fallon, who has been filming segments with U2 around New York City all week in preparation for the May 8 episode of The Tonight Show, which is reportedly what the pop-up performance was for. The band’s Tonight Show appearance comes six months after their originally scheduled week-long stint, which had to be postponed due to Bono’s bike accident in November 2014.