Todd Rundgren, Hammersmith Apollo, London

To a certain generation of former furry freaks, now bald retro-rockers, Todd Rundgren inspires fierce devotion. The American eccentric's success as a producer, supervising sessions for the Ramones, Meat Loaf, etc, gave him financial independence. Hence, if he wanted to make something as off-kilter as A Wizard, A True Star, a concept album with no concept, he could. Now he's touring the LP for the first time – 37 years late. Rundgren may be an oddball, but there are 3,500 elders here who see him as a True Star. And they have a point.

Before their view could be confirmed, they had to sit through Todd Rundgren's Johnson, a sloppy quartet in black T-shirts blasting out pub versions of Robert Johnson's much-milked catalogue. Here was a musical sophisticate tackling roots that were never his: quite odd.

The Wizard set was peculiar for different reasons. Johnson returned to the stage in white tailcoats, augmented by two keyboard players and a saxophonist, for a complex revue. The album is a cityscape of beautiful three-minute pop symphonies amid a suburban sprawl of Moog melodies, gags and rock'n'roll. It is not prog, since the songs were short and memorable. If it's psychedelia, it is rooted in Rundgren's Philadelphia childhood. It is quite an ask for seven people to perform.

Perform it they did, almost flawlessly. Sans guitar, Rundgren appeared a limited front man in Nasa spacesuit for "International Feel", hence numerous changes of costume. But he grew into the role, and his confession in the wistful "You Don't Have To Camp Around" added a taste of real life. "When I was a lad 'gay' meant 'carefree'," he deadpanned, all velvet and frills. "And there wasn't a single gay person in my family." His Humpty Dumpty burger-flipper outfit for "Just Another Onionhead" was bizarre, yet in the same garb he wrung all the angst from "Sometimes I Don't Know What to Feel". Written when he was just out of his teens, at 61 he meant every word.

Ridiculous, hilarious, awkward and awesome; at the final curtain you were surprised at how moving the show was. If Rundgren had selected a straight career trajectory, he could have been America's Bowie. But he would never have produced such a testament to youthful confusion as A Wizard, A True Star. Nor would he still be capable of creating a show as strangely spellbinding as this.