Welcome back, Britney! Tonight, Britney Spears and Iggy Azalea performed their single “Pretty Girls” for the first time at the Billboard Music Awards in Las Vegas. The single is meant to promote Spears’s ongoing residency in that city, and the performance served as an apt advertisement for the pop star’s stage show: Spears, who’s performed on television rarely since her 2007 “Gimme More” fiasco at the MTV Video Music Awards, seemed both with-it and truly delighted to be onstage. Azalea, who’s come under fire online in recent months for her acuity with rapping live, sold her verse, too. As redemption stories go, this one couldn’t have been more welcome.