In their 1970s heyday, the idea of "New Waver" Joe Jackson sharing a stage with an "old guard" like Todd Rundgren would have been as likely as Carter going for a pint with Brezhnev. However, in pop's latter-day Glasnost, barriers have come down. Jackson dabbles with string sections while Rundgren has turned his hand to computers.
Perhaps Rundgren's presence has awakened Jackson's old edge. His solo set - firing spittle across a grand piano - shows that only Elvis Costello beats him when it comes to agitated, savagely observational songs. A killer new composition compares 15- and 40-year-old alienation. Real Men and Different for Girls timelessly explore preconceptions of femininity and machismo and, of course, Is She Really Going Out With Him brings the house down.
In his 1980s power-suit and shades, Rundgren looks like the lead in American Psycho after a night on the tiles - and plays like it. Britons never really "got" his brash Americana, and those that did must be bewildered to hear long-unaired classics like I Saw the Light tossed off on guitar.
But both Rundgren and Jackson are clearly hungry for new challenges, and a gauntlet is hurled down as Jackson returns with Ethel, a fiery, spiky New York string quartet. Together, the sextet rampage through Jackson's Got the Time and Rundgren's confrontational Stood Up. By the time they've taken the Beatles' While My Guitar Gently Weeps to places it has never visited, this unlikely collaboration starts to feel like it could be the making of all concerned.
· At Hammersmith Apollo, London, tonight. Box office: 0870 606 3400.