Ben Harper is a wildly eclectic singer-songwriter and guitarist with a career on fast-forward. But there is something of a problem: nearly 10 years after the release of his first album, his status is somewhere between rootsy cult hero, famous for his remarkable array of styles, and a pop star who can pack out the enormous Brixton Academy for two nights and attracts screams from female admirers. Growing up in California with a black father and white mother, he listened to everyone from the delta blues singers to Bob Dylan, Marvin Gaye and Bob Marley. All those influences were reflected here - along with a hefty dose of Prince, funk and rock.

An athletic-looking figure in blue jeans and T-shirt, he was surrounded by an all-purpose American band. He started out as if this were a bombastic rock show (with often terrible sound), but then switched styles. So a blast of R&B and funk gave way to an equally pounding burst of blues, with Harper sitting down to play slide guitar on Temporary Remedy. Then he showed off his easy-going soulful vocals on When She Believes, scored even higher on the scream-register with his version of Gaye's Sexual Healing, and changed direction again with the rolling country-rock of Diamonds on the Inside, which kicked off with a guitar and organ-backed introduction worthy of mid-period Dylan.

During the encores, he changed styles yet again. He played acoustic guitar for solo treatment of early introspective songs like Walk Away, showing off his fine soulful vocals, then brought back the band for a rousing reggae finale, which included his own With My Own Two Hands and Marley's far superior War. This was 1970s nostalgia with a difference. Harper is an impressive singer and guitarist who can echo the styles of his many heroes, but by doing so he invites comparison. His own material may be intriguing and pleasant, but it lacks the power of the old classics, and so the best songs of the night were inevitably the cover versions.