The House of Mirrors & Hearts, Arcola

Musicals are cheesy by nature, aren’t they? If not cheesy, then picturesque. The cast of Les Mis may be grimy and poor, but they’re picture-postcard poor. Even modern musicals play by the rules.

But Aemonn O’Dwyer and Rob Gilbert break most of them in their new musical, The House of Mirrors & Hearts. Forget exotic settings: this type of family terrace house can be found by the thousand off the Kingsland Road. And forget happy families: this one’s falling apart. What’s more, the climax of the first act is a grisly accident involving a character we haven’t even met. And two of the key characters are kids. This musical isn’t just ripping up the rulebook - it’s tempting disaster.

And yet it comes off. Better than that: it has psychological truth and, for all its militant domesticity, largely keeps you hooked. I only started to wilt when a character opened the fridge for what seemed like the 110th time (aren’t there other things to be done in a kitchen?). What makes even the slow bits watchable is the all-round fabulousness of Gillian Kirkpatrick in the role of Anna, a one-time loving mother undone by grief and an all-day, every-day Merlot habit. She turns her big drunk number, “Something for the Pain”, into a showstopper.

Almost as scary is the aplomb of Charlotte Pourret Wythe as eight-year-old Lily who, along with her 11-year-old sister (Sophie Pourret Wythe) finds her life shattered (and that’s not the cliché you think it is) one evening at home with their parents. Dramatically, the cast is strong, and although the vocal styles of Molly McGuire’s nymphomaniac Lily and Grace Rowe’s withdrawn older sister Laura are mismatched, it suits their characters. McGuire hasn’t yet graduated from drama school and her voice is already a powerhouse. Rowe’s delicacy draws us in.

In other roles, musicals veteran Graham Bickley is David, raffish man of the house and one-time artisan producer of fancy mirrors, while Jamie Muscato is ardent as the lodger Nathan, a young academic cataloguing the works of an 18th-century poet, “Alexander Thornton Gray”, an amalgam of Alexander Pope and Thomas Gray of the famous Elegy. Quite why the uptight Nathan persists in renting a room in this oestrogen stew of a house where he’s hit on by a 15-year-old every time he appears for breakfast is anyone’s guess. Yes, of course, if he left, there wouldn’t be a story.

At least two of the songs draw their lyrics from Thornton Gray’s putative poems – a crafty way of varying tone and texture – and on the whole the musical numbers are stronger than the dialogue, which occasionally clunks. The tunes may be unmemorable, but many are pitched in a harmonic no man’s land which plays well to the emotional instability that drives the plot. Instrumental support is provided by an excellent trio (hidden under a staircase) led by pianist David Randall.

The best scene is when Laura and Nathan let off steam and find each other by hurling her mother’s empty wine bottles against a wall. Broken glass and broken hearts, mirrors and mirror-images – it all ties up rather neatly. This is a bold if patchily inspired attempt to break the Von Trapp mould of the unhappy-family musical.

• The House of Mirrors & Hearts runs at the Arcola Theatre, E8, to 1 August 1st