Beyonce and Jay-Z party at South Beach Karaoke Bar

Beyonce, eft, and Kelly Rowland surprise fans at South Beach Karaoke bar. Courtesy/Sing Sing/Twitter

Beyoncé and Jay Z are taking full advantage of all the luxuries Miami has to offer.

From late-night scooter rides around South Beach to dining at hotspots such as Zuma, SeaSalt and Pepper, Casa Tua and Soho Beach House (with daughter Blue Ivy, who turned two on Tuesday) the power couple are living it up.

Along with their private time, they are also spending time with their friends - and some lucky, unsuspecting fans.

Early Wednesday morning, Bey, Jay, Destiny's Child singers Michelle Williams and Kelly Rowland, and rapper, Timbaland paid a visit to Sing Sing, a karaoke bar located at 717 Washington Avenue in Miami Beach.

That's when -  inside the empty club - the megastars gave a group of girls the shock of their lives.

Sing Sing's owner Kellie Pilicer told Us Weekly that Bey, Williams and Rowlands surprised three lucky fans who were actually singing Beyoncé's song "Party" in another room.

"I was showing Beyoncé how to work the remotes and she asked me where the music that was playing [in a separate room] was coming from," Pilicer told the mag. "And I said 'Oh don’t worry, it wont bother you.' And she said 'No, I want to see who is singing my song." 

"Beyoncé and Michelle started singing and dancing with them," Pilicer added. "They were also videotaping the whole thing. These girls had no idea it was them for the first couple of minutes. It was cute." 

Later the pop stars took a photo with the girls, and even photobombed one girl who had fallen asleep.