Kurt Elling, Pizza Express Jazz Club, London <!-- none onestar twostar threestar fourstar fivestar -->

If you combined the masculinity of Frank Sinatra with the smoothness of Tony Bennett and added the theatricality and fondness for versifying of the late Lord Buckley, you might begin to approach the remarkable range and delivery of Kurt Elling. There are few vocal artists today who can come as close to encapsulating what a jazz singer should be than this 38-year-old Chicagoan, who has been playing to packed houses at Soho's Pizza Express.

Artist is the right word; the way Elling shapes a standard such as "My Foolish Heart" or "Stairway to the Stars" is on a different plane from the singer who merely states the melody, however prettily. With immense variation in dynamics and complete command of pitch and intonation, Elling phrases songs into vocal sculptures. The lush, cello-like legato he employs in, say, "Close Your Eyes" or "Change Partners and Dance With Me" produces billowing shapes underpinned by the rock-solid bass and drums of Robert Amster and Willie Jones III.

Elling is aided in this by the remarkable empathy he has with his co-songwriter Laurence Hobgood, whose crystal-clear piano-playing provides the perfect foil to the singer.

All three of Elling's sidemen rise instantly to his command when he wants to raise the flame after a slow intro into a fast four, and then the singer can turn to another weapon in his armoury: super-articulated, rapid-fire scat of the kind that could blow most horn-players off the stage.

In this mode, or in the related mode of vocalese, when Elling is singing words he's set to Dexter Gordon's solo on "Body and Soul" or a section of Coltrane's "A Love Supreme", the leader is a man possessed. His body twists and jerks; his eyes appear to roll backwards; standing back to let out a loud holler, his mouth opens, horse-like. The spirit of jazz speaks through him, leaving him sweating and drained when it chooses to allow him to return to human form.

Not that Elling flags in any way, giving the audience full value for money with two long, high-octane sets. It is very full-on. Some people are scared by this kind of jazz singing, he told me afterwards. But Elling is at the height of his powers, and I cannot think of any vocalist who can currently match him in this territory. A little awe in the presence of music this powerful is quite appropriate.