I hadn’t heard Ian Shaw before, but I’d certainly heard of him. A British male jazz vocalist – there aren’t very many. A US recording contract – doesn’t grow on trees. Rubbing of hands by the musicians at “the spin @ the wheatsheaf” that they’d managed to book him for last Thursday.

As befits a male diva, he didn’t appear for the first number but left his usual accompanist James Pearson on electric piano to take the resident trio for an invigorating run round a fast bop number. His entrance wasn’t exactly grand – he had to squeeze his considerable frame between closely packed tables of punters, then climb onto the stage. But from the moment he turned to the audience and started with a strange scat intro to All or nothing at all he had everyone in the palm of his hand. Not just the audience, but the other musicians too. He was the act, they were the (awesomely competent) backing band.

Ian Shaw will never be knighted, but he’s an authentic national treasure. In the first place, it’s sheer technique: incredible range of pitch, from falsetto to deep growl, and of dynamics, from full-throated shout to barely audible whisper. But part of what mesmerises the audience is that he uses the wonderful instrument of his voice just to play, for the sheer joy of it. One moment he’s wrapping himself wholeheartedly round a lyric, next he’s using his voice to mock it, then he’s off on an improvisation, but not for long because soon he’s finding it boring and starts parodying himself. But beneath the playfulness and the parody there’s seriousness. Part of his appeal is that he lets his emotional vulnerability show, but just as you think he’s going to tip over into sentimentality, he’s changed direction. Mercurial, and inimitable.

Roger van Schaick