Here We Are is full of wit and flair, but Stephen Sondheim’s final musical feels incomplete

A posthumous premiere from a composer so respected that his nickname is simply “God” is, to put it mildly, a pretty exciting prospect for musical theatre fans. And that’s before you factor in its formidable, if unlikely, cast. Transferring from off-Broadway to the National Theatre with a new lineup of actors, the late Stephen Sondheim’s Here We Are is a surreal apocalyptic comedy, which stars Jesse Tyler Ferguson (Modern Family) as a henpecked plastic surgeon, Harry Hadden-Paton (Downton Abbey) as a foot-fetishist bishop, and Jane Krakowski (30 Rock) as an interior designer wafting about cluelessly in a negligee. They just want to go for brunch. But the universe has other ideas, as this stylishly weird, unfinished musical descends into an existential satire of the feckless rich.

As his career wore on, Sondheim became increasingly interested in using musical theatre as a space for psychological exploration, choosing abstracted, liminal settings for works such as Follies (1971) and Into The Woods (1986). Even so, we’re on strange, shifting ground here, with a story grafted together by playwright David Ives from two surrealist films from Spanish-Mexican director Luis Buñuel: The Discreet Charm of the Bourgeoisie and The Exterminating Angel. It follows a group of wealthy friends marauding around the city in search of something delicious to eat: Sondheim’s score is on urbane, jazzy form as they go to an array of bougie restaurants, only to have their appetites tormented by an empty kitchen, a chef’s funeral, and rubber food.

Unusually, these friends mostly sing in chorus together (which explains the casting of stars who aren’t musical theatre regulars) with the solo songs coming from incidental characters such as Denis O’Hare’s beautifully rendered array of servile attendants. “The Waiter’s Song” is a jaunty comic delight, stuffed with Sondheim's signature wordplay: “We do expect a little latte later but we haven’t got a lotta latte now.” Ives’ script is full of wit, too, satirising the image-obsessed triviality of this crew: “Oh did I tell you, we’re getting the dogs cloned,” pronounces Krakowski’s character, who wants identical poodles to greet her in each of her many homes.

Tony Award-winning director Joe Mantello throws body, soul, and a huge amount of cash into making this oddity work – David Zinn’s astonishingly lavish set design magics up an array of rooms that ought to be preserved in the Met, gorgeously gilded and mirrored, melting into each other and then into the bright, blinking white of nothingness when these friends’ meaningless lives melt away. It’s flip, funny, and undeniably stylish. But essentially unsatisfying, too.

An exhaustive eight-page essay in the programme charts the musical’s four decade-long journey from idea to stage, its progress dogged by indecision, the lure of other projects, and procrastination (at one point, Sondheim claimed he couldn’t compose because of an ingrown toenail). In the end, Sondheim died before Here We Are was finished, meaning that the second half of the play is largely bereft of musical numbers. Instead, it descends into a locked-room drama where comfortable privilege descends into ugly anarchy, and rich man’s daughter Fritz (Chumisa Dornford-May) abandons her revolutionary principles in favour of a boot-cupboard tryst with a soldier as the world starts to burn.

What’s being attempted here is an act of transubstantiation: the trivial turned into the profound, as these superficial friends are forced to reckon with death and immortality. But Sondheim was tragically unable to finish the songs that would elevate this musical into the transcendental thing it could be. Instead, it’s a beautifully rendered curio for his fans, full of wit and dash – and a testament to his restless search for meaning in the most unexpected of places.

At National Theatre until 28 June; nationaltheatre.org.uk