Posted by Adam

Sunday September 6, 2009

Britney Spears proved her singing credentials during her gig last night in Greensboro, NC — she performed a (live!) cover of Alanis Morissette‘s classic You Oughta Know.

It’s the first time Spears, 27, has sung live on her Circus tour, which began in March.

“We were really surprised!” said a concertgoer of Spears’ impromptu performance. “Nobody knew she going to sing that song. When I saw her rise up with a microphone I was thinking, ‘what is she doing?’ I had to ask the person in front of me what song she was singing!”

Previously on the tour, Britney has lip-synced while concentrating on the complicated dance routines involved in the show.

Tags: britney spears