"So you think electronic music is boring … stupid … repetitive?" inquires a male voice at the start of Mozart's House, the penultimate number of Clean Bandit's main set. Then, disarmingly, it adds: "Well, it is repetitive." It's hard to know what to make of that – as with other aspects of this show, it's not what one expects of a dance-pop set. This Cambridge-educated foursome are genre oddballs. Their sound is grounded in familiar-sounding house and garage, but there's a major point of difference from their friends Disclosure and Rudimental: the beats are counterweighted by classical flourishes produced by violinist Milan Neil Amin-Smith and cellist Grace Chatto.

On stage, the tokenistic string garnish heard on this year's smash single Rather Be is expanded to the point where Amin-Smith and Chatto comprise the heart of the sound. The rest of the band – drummer Luke Patterson, his brother, Jack, on decks, and blistering hired vocalists Elisabeth Troy and Florence Rawlings – are rather overshadowed. Amin-Smith and Chatto, who plays a futuristic instrument that looks like a sword, veer from Tchaikovskyesque prettiness to eastern European klezmer, creating a genuinely unusual hybrid.

The fusioneering can go astray: Rihanna (a tale of getting jiggy while listening to her records) and UK Shanty evoke the Hooked on Classics classical-disco era, and Mozart's House has a hoedownish madness not dissimilar to Switzerland's Eurovision entry. Moreover, this sold-out gig proves that a band can't choose their fans. Up in the balcony, the teenagers drawn by Rather Be (played as a fierce double-dip encore with a cover of Robin S's house anthem Show Me Love) are shunted by a crew of rugger types who look like they're continuing a party that started at Prince Harry's pad. Overall, though, an entertaining evening for the right reasons.

• At No Tomorrow festival, Nottingham (0845 413 4444) on 7 June, then touring. More info at cleanbandit.co.uk