Rihanna's karaoke night for pal's birthday

Rihanna took over a bar in London on Wednesday night (12Oct11) to stage a karaoke party for a tour crew member's birthday.

The Umbrella hitmaker is in Britain for a string of shows, but during an evening off from performing she took a group of her workers for a night out at the U.K. capital's Nove Karaoke Bar.

The Bajan beauty hired out the venue to mark an aide's birthday, and they celebrated in style with a feast of pizza and garlic bread, accompanied by beers and vodka shots.

Rihanna also took to the microphone to perform renditions of several songs, including Kings of Leon's Sex on Fire and her own track Take A Bow.

Emma Citron, who worked behind the bar during Rihanna's visit, tells WENN, "They spent over $1,600 at the bar. It was really fun, a great night."

The pop superstar left the karaoke venue after three hours inside and headed onto famous strip club Stringfellows.