Prince has always been an artist's artist and a musician's musician, so assembling a super-session of British soul-jazz talent to play his tunes is a no-brainer. The Jazz Cafe's latest "Happy Birthday To Ya" show features a terrific band including bassist/MD Nick Cohen, drummer Frank Tontoh, saxophonist Jean Toussaint and guitarist Tony Remy. Noel McKoy, in a purple three-piece suit, is the genial MC, introducing a succession of singers to the tiny stage: Don-E, Nate James, Lennox Cameron (also playing keys and flute) and Z-star.

McKoy himself delivers a tense, terse rendition of Sign O' the Times and a florid Purple Rain. The whole evening is packed with fantastic songs: When Doves Cry, Take Me With U, Raspberry Beret and so on. But there's a thin wobbly line between being a collection of stars paying tribute and being just another tribute band.

The songs are so well written and structured that it is hard for an artist or band to impose a fresh interpretation on the material. So it is good to hear James try something different with When Doves Cry, and Don-E doing his funky voice-box keyboard thing on Do Me Baby, which he and the band deliver as an expansive soul ballad firing on all cylinders.

The real surprise of the evening is newcomer Z-star, who takes possession of If I Was Your Girlfriend and Sexy MF like there's no tomorrow, with range, power and style - plus that extra sense of the ridiculous you need in order to get under the skin of Prince's grand designs.

When everyone returns for Kiss, the final encore, Z-star does it again: she's a soul- jazz diva to watch out for. Driving home, I notice that the National Theatre's fly tower is bathed in purple light. I think Prince, in his prime at 47, would have appreciated that.