Blue States, Bloomsbury Theatre, London

From the look of him, Blue States' Andy Dragazis, is not into "trimmings". Blending chameleon-like into this modern theatre's dark, black stage, his look is more casual nondescript than bold, talented musician. "The problem with playing gigs is that you have to get dressed up and wear ill-fitting shirts," he explains, unapologetically, to the expectant, thirtysomething crowd. But first impressions shouldn't be trusted. Dragazis may not make much effort with his personal presentation, but this one-off orchestra-performed gig set against tailor-made visual backdrops, is served up cherry and all.

Crammed on to a stage teeming with microphones and music stands Dragazis, Blue States' vocalist Tahita Bulmer, and 10 others (including a cellist, two violinists, two trumpet players and a percussionist) beautifully recreate the soulful chilled-out beats of Blue States' two opulent, instrument-laden albums – last month's Man Mountain and their 2000 debut Nothing Changes Under The Sun. Gloriously sunny trumpets, melancholy strings, tenderly strummed acoustic guitars and funky, slapped bass lines are carefully woven together and layered until the merged sounds swell and overflow, just as they do on the albums.

But live, Dragazis's songs have even greater momentum. The tambourine in "Studio 20" takes on a driving, hypnotic quality, while an added harmonica brings a brighter dimension to "What We've Won". Even Bulmer's voice, which at times on Man Mountain is no more than a weary soprano, sounds strong and deep, backed by the driving strings that force the leading guitars to take a back seat. It's just a shame that she goes through the entire set without cracking a smile, preferring to wear a rather serious pout instead.

For the most part, the short films that accompany each song (projected on to a huge screen above the band) are simply soothing eye candy, featuring calm, swooping, aerial shots of serene landscapes; sepia-tinged nostalgic images or cheesy, split-screen sky views. But there are notable exceptions. The monochrome firework explosions synchronised with the early single "Trainer Shuffle" invite you to surrender to this ethereal, strange and sad song. And, saving the best until the final encore, Elios Therapia's fast-paced, colourful peek at a seaside promenade is filled with the bitter-sweetness of tear-stained smiles. The loud eruption of whooping that follows proves that this is the song everyone has been holding out for.

Visuals aside, Dragazis's lush and glamourous 60s soundscapes are so sonically enveloping that – pictures or no pictures – all you want is to be submerged in them. Eyes closed, heart open.