Extra Once 2Once is a rare wonder of a show. Based on the Oscar-winning film, this Tony and Grammy-scooping musical will wound and lift your heart and demands to be seen. And if you can, see it before May 10th for a chance to witness Arthur Darvill stepping firmly out of the shadow of Doctor Who to deliver a performance of tremendous power and nuance.

He’d already been captivating as the local vicar in ITV’s brilliant Broadchurch but here, as the bashful, simply-named ‘Guy’ to Zrinka Cviteši?’s gregarious and sweet ‘Girl’, Darvill’s presence, vulnerability and impressive singing confirms he’s a young British actor to be reckoned with.

That said, he’s blessed with some fantastic material in a gorgeously rendered show. A ramshackle band play on the stage of the Phoenix Theatre as you take your seats, with the boards that played host to Blood Brothers for so many years now transformed into the interior of a Dublin bar, with Jameson lining the walls and On Grafton Street blowing through the aisles. There’s an instantly evocative and convivial feel to the show and space is used smartly and efficiently throughout, as the bar becomes a bedroom, a bank, and even a beach.

It’s a boy meets girl story with a difference, with music the uniting force between the pair, and their salvation. ‘Guy’ has put his dreams of a singing career on hold and moved in with his father after being left brokenhearted. ‘Girl’ is thousands of miles away from her native Czech Republic with her daughter and mother in tow in Dublin but her husband back at home. Cviteši? is a marvel, with her part greatly expanded from the film’s quiet and pliant original character to a more forceful, candid woman who instigates the relationship that changes the protagonists’ lives.

Over five heady days, they meet, sing together and attempt to record an album together, mixing all the while with her ragtag group of flatmates, a bank manager with singer-songwriter aspirations and a music shop manager who carries a torch for ‘Girl’. Book author Enda Walsh has crafted a dry, consistently funny script, with wry observations about the annoying ‘combination of Cork and banker’ and a plaintive cry from ‘Guy’ of ‘I don’t want to be Bono!’ There’s warmth and wit and wisdom throughout while the constant on-stage presence of the ensemble cast makes this show about big dreams and great love feel deeply intimate.

The key, however, is the songs, with Glenn Hansard and Marketa Irglova’s original movie tracks, already full of bittersweet feeling, given new life by the cast. Darvill – who can’t help but look a lot cooler than the rough-edged Hansard – brings raw feeling to his lovelorn solo efforts while Cviteši? has a clarity and power that makes the breakup ballad The Hill all the more devastating. Falling Slowly, an Oscar winner in 2006, has become more touching as the full band enhance its plaintive hope while Gold appears twice, the second time with astonishing minimalism.

To borrow from the show’s Dublin vernacular, it’s a deadly musical. But in any dialect, it’s a show of singular beauty and emotion. It’s creatively thrilling and emotionally striking, with two wonderful actors leading a superbly talented cast of actor/musicians. See it once, see it a hundred times; just see it.