For a recently graduated threesome of thrash-jazzers more used to student dives in Leeds than a world of TV interviews, stadium-band hardware stacks and glitzy light shows, Roller Trio played their preview gig for the Mercury prize with the same wild insouciance that has made their sound a howl of fresh air. The transformation of LSO St Luke's into a TV studio didn't faze them, nor did an audience principally present to hear the show's big star, Devon singer-songwriter Ben Howard. The word on the floor was that Howard sounded like a Mercury frontrunner, and in his short set – a tight display of folk-troubadour's imagination, hard-rocking ensemble energy and plenty of offhand charisma – he certainly advanced that speculation.

Preceding Howard on stage, Roller Trio ran through six tracks from this year's eponymously titled album, opening with the alternately raucous and thoughtful Deep Heat. It featured a snorting, braying, loop-like tenor saxophone figure from James Mainwairing that gets wrapped in Luke Wynter's guitar lines and buffeted by Luke Reddin-Williams' seething drumming. Rollertoaster began with a low-end sax growl against jangling guitar sounds; these developed into fascinating stories, owing as much to eastern as western scales in the hands of the resourceful Wynter. Impressionistic, echoing sax whoops hovered across cymbal-edge textures; rocking, minimalist themes turned into the collective eruptions of noise that link this band with the now defunct Acoustic Ladyland and the very active trio VD (a significant Leeds inspiration). Against those contrasts, a quiet passage, as shapely as a folk song, showed just how a balance of the inviting, the funky and the uncompromisingly abrasive has brought Roller Trio its enthusiastic new audience – and its Mercury nomination.

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