Britney Spears is set to surprise fans with a one-off appearance on Cyndi Lauper's True Colors tour when it arrives in Los Angeles on Saturday (30Jun07). The Toxic singer will perform one song at the Greek Theatre gig, which will also feature Lauper, Erasure, Debbie Harry, The Dresden Dolls and The MisShapes with Jeffree Star. Spears will take the stage with two female backing dancers, her choreographer Misha Gabriel tells website People.com. She last appeared live in May (07), when she lip-synched her way though a series of brief 15 minute concerts.