The Poker Face singer headed to the SixtyFive venue in the early hours of Wednesday morning (24Jun15) after finishing the final show of her Radio City Music Hall residency with Tony Bennett on Tuesday (23Jun15).

Gaga was joined by Bennett and his family, as well as her own relatives, for the post-show bash, and she surprised fellow party-goers by taking the microphone for an impromptu performance.

She sang the standard Just a Gigolo and Bang Bang, while her longtime pal Tommy London, the singer of rock group Dirty Pearls, also performed, according to New York Post gossip column Page Six.