Trombone Shorty, Jazz Café, London

Troy Andrews, aka Trombone Shorty, is a 25-year-old wunderkind from Treme, New Orleans who's been making music since he could talk (and walk) – the moniker came from marching in a street parade aged four wielding a trombone twice as long as he was high.

It's a name that has stuck, though Troy is all grown-up now, wielding his instrument like a child's toy – his six-strong group, Orleans Avenue, just about squeezing onto the Jazz Café's bandstand. There's a real physical energy on stage. This is the sound of New Orleans after the flood, in the hands of a new generation. Shorty calls his music "supafunkrock" and that's a tight description of the sound blasted out to the packed-out venue.

The focus is on his second album, Too True, which featured a raft of guests – Lenny Kravitz on bass, guitarists Jeff Beck and Warren Haynes, singers Kid Rock and Ledisi – but here in Camden, it's down to Shorty and his six-piece – two sax players, turbo-charged drums and percussion, a fine guitar player in Pete Murano, bassist Mike Ballard rumbling like an overheated boiler and Shorty himself, wielding trom-bone and trumpet and taking the mic as lead singer and conductor.

The music on stage is stronger, harder, with greater pressure and bottom-line than it is on record. The set's openers are tough instrumental workouts, featuring choppy rhythm guitar, a chattering interplay between drums and percussion, and waves of brass falling in around the tremendous weight of the bassline – carried by Mike Ballard as well as guitarist Murano, underpinning the riffs in grungy lower registers.

Shorty's singing has a lot of soul and funkiness, but the voice – and the generic booty-call lyrics – are no match for the physical energy the music picks up and throws out.

It's the instrumentals, the jams, and a marvellous James Brown tribute of riotous, almost punk-like energy that captures the crowd and generates the most heat. It elicits a great roar of audience approval and the energy is sustained through to the encore of "Do to Me", with Murano ably filling Jeff Beck's album solo, and Shorty stepping back from the mic to conduct the dynamic of the band with the energy and enthusiasm of a real fan – as well as a captivating frontman.