Britney Spears Parties in Pittsburgh

Britney Spears tosses her hair as she rocks out at a performance in Pittsburgh, Penn. on Friday night (March 27).

Also pictured below is Brit-Brit performing her heart out for fans at Nassau Coliseum in Long Island, New York.

The 27-year-old singer’s dad, Jamie Spears, has sent a notice to BreathHeavy.com, one of Britney‘s fans sites, to shut down by 3pm today or face an injunction. The site has been critical of the conservatorship arrangement with Jamie, who makes $18,000 a month.

40+ pictures inside of Britney Spears performing in Pittsburgh…