Colbie Caillat surprised a group of fans Saturday afternoon when she showed up at the Central Perk pop-up shop in New York City's SoHo district.
Wearing jeans, a white top and brown boots, the 29-year-old singer stepped up to the microphone to deliver an unannounced performance of Phoebe Buffay's beloved song, "Smelly Cat."
"Smelly cat, smelly cat what are they feeding you?" she sang. "Smelly cat, smelly cat it's not your fault."
"That was COOL! Singin @ #CentralPerk," Caillat tweeted after her visit. "My favorite show ever #Friends20."