Jamie's all-star jam

Press photographers are like taxis and policemen. There's never one around when you need one.

Early in this sold-out London Jazz Festival show they were everywhere, kneeling intrusively between tables to snatch their action shots. But all had vanished when, early in the second set, Jamie Cullum played his trump card and plucked Peter Cincotti from the audience for one of the most spontaneous all-star jams of the year.

High jinks ensued as the tall New Yorker and diminutive Londoner exchanged places at the mike and the piano bench for an impromptu version of I Could Write a Book.

Jamie, of course, has enough material to do so, having toured the world this year and set his version of Everlasting Love to the soundtrack of the latest Bridget Jones movie. Ticketless fans could also have caught him on BBC1 last night, in concert at Blenheim Palace.

The sporting Cincotti, Jamie's closest rival, headlines at the Royal Festival Hall tonight while Jamie returns to the 606 Club as part of his payback tour of the small venues where he got his act together.

It was here at Dean Street, too, that he'd queued to hear his US hero Kurt Elling sing. "I've been everywhere this year," he reflected, "but this is the most nervous I've been for months."

Nerves, however, have always had a positive effect on Jamie, who hit his stride immediately with selective standards (I Get a Kick Out of You, Have You Met Miss Jones), quality pop (We Never Change, by Coldplay) and originals, including Twentysomething and a promising newcomer, Love is the Sweet Solution. "This one," he quipped, "is for Bridget Jones-5." Martin Taylor (supportive guitar on Djindji) and Shola Amah (soulful vocals on Feel Like Makin' Love) were other welcome guests on a night when Jamie and his faithful trio, with drummer Seb de Krom and bassist Geoff Gascoyne (a Jurgen Klinsmann double with his new pop-length hair) exuded star quality. Jamie's piano technique keeps improving, but one lesson he has yet to learn after a typically overdrawn finish is Always Leave Them Wanting More.

Festival continues until Sunday 21 November. Information: www.serious.org.uk and www.bbc.co.uk/radio3