It's midnight when Little Dragon take to the main stage, during the closing hours of Worldwide. Cloistered at the far end of a breakwater, beneath the soaring Phare du Mole lighthouse and just feet away from the Med, it's a stunning setting. At the other end lies Sète, a charming and utterly unpretentious French fishing town built around a network of canals (the "Venice of Languedoc", or something equally optimistic). For the last nine years this seven-day festival has absorbed thousands for this yearly outing, curated by radio hero and music purveyor extraordinaire, Gilles Peterson.

As the locals sleep nearby, there's huge anticipation for the band among the crowd. The line up so far has been near impeccable - an eclectic palate of house, techno, disco, garage, funk, underground Brazilian beats, dancehall, dubstep - but dominated by DJs. So a big live act in the main St Crist arena is a refreshing prospect.

Illuminated by dazzling lights and neon strips, the two keyboardists Fredrik Källgren Wallin and Håkan Wirenstrand (whose bushy, Nordic beard really demands a slot of its own on the bill) flank the stage, the most withdrawn and demonstrably Scandinavian of the band. Meanwhile, their cocky showman of a drummer Erik Bodin, clad in a luminous khaki playsuit, runs around the stage before settling at his kit. After a synth-drenched intro, Yukimi Nagano, their joyously charismatic singer, bounces on stage. For what the set lacked in length (just one hour - we could have easily enjoyed double this), the progressive pop quartet go on to deliver one of the most memorable 60 minutes of the entire festival.

A wobbly start on the vocals - more the fault of the sound booth than Nagano - rapidly morphs into an energetic, near-flawless show, if only in terms of sheer musical refinement and effortless control. There is minimal chat between tracks but equally, little silence, with each tune seamlessly merging into the next. Nagano is magnetic to watch, despite remaining almost oblivious to the audience, enraptured by the music.

Boosted by an artillery of trustworthy Funktion-One speakers, songs from their new album Nabuma Rubberband provide the bulk of the gig - soaring vocals on 'Killing Me', the dreamy liquid pop of 'Paris', their recent belter of a single 'Klappklapp', and the dark, melancholic 'Only One', which explodes into an expansive, rave-heavy climax. The focus, however, is on extended passages of music over vocals; perhaps something is lost compared with other Little Dragon performances in smaller venues, where Nagano's voice and lyrics take centre stage. But it's a minor quibble. Masterfully executed, the band's interludes of deep, rolling house are a fitting tribute to Worldwide's celebration of club culture and a high note to the festival's end.