Each time they return to the UK, the Grammy-winning American jazz-funk collective Snarky Puppy draw increasingly ecstatic young converts into bigger venues. Their current tour's sold-out nights at London's Scala showed the tide still rises for these unassuming self-made stars and their spirited repertoire of horn-hollering soul hooks, floor-shaking beats, and punchy improv. Some might doubt the group's improvisational skills while admitting their irresistible groove power, but their second Scala night turned out to be an unexpectedly successful balance of the two.

The band's English sideman Bill Laurance opened the show alone with some quiet keyboard musings that soon cranked up into a thumping hook as the others showed up. Bass guitarist Michael League handclapped with the laughing crowd as sly drum-hits kept throwing off the expected beat (the teasing wind-up snaking towards the anthemic pay-off is a favourite Snarky game). A wailing reeds-and-brass riff was enveloped in a molten clamour of clanging guitar chords and dense two-keyboard harmonies, before the emergence of a snorting, bop-like fast funk theme.

"That was our Britney Spears cover," League said (it wasn't, though the others dutifully busked snatches of Hit Me Baby One More Time behind him). The infectious What About Me? (from new album We Like it Here) had saxophonist Chris Bullock opening with lush swing-tenor figures, but soon sprinting nimbly through a churn of wah-wah sounds. After an hour, the band grew more impressionistic and improvisational - a guy on the balcony amiably yelled "Where did it go?", but a cooler feel, hanging cannily behind the beat, had its own kind of seductiveness.

League picked his moment to introduce exciting young British percussionist Felix Higginbottom (a student who had joined Snarky's masterclasses at Manchester's Band on The Wall last year) for a gleefully galloping Brazilian feature that drove the energy-level right back up to eleven.