Lady Gaga returned to the stage on for the first time since undergoing hip surgery after making an unannounced appearance at a New York bar late last week.
The singer has been in recovery since receiving treatment on to fix a hip injury in February.
The surgery prompted her to cancel the remaining dates on her Born This Way Ball world tour.
After spending weeks in a wheelchair Gaga decided to step back into the spotlight by joining her pal, jazz musician Brian Newman, during his regular performance at the Gramercy Park Hotel's Rose Bar on Thursday. She sang George Gershwin's anthem Someone to Watch Over Me to the surprised crowd.
After the show, Newman took to his Twitter page and wrote, "Thanks to the 1&only @ladygaga for coming out to @GPHhotel tonight."
Gaga is no stranger to Newman's gigs - she has previously performed with her friend at the Oak Room bar at the city's Plaza Hotel.