For all our fascination with musicals, it’s not often you see a bona fide, literally showstopping number. Dominic Cooke’s National Theatre production of Follies – returning to the Oliver after its award-winning first run in 2017-8 – boasts two in succession: “Who’s That Woman?”, known to the veterans of the former Weismann Follies as “the mirror number” and in which decades of the show’s past stars both (re)unite with one another and face up to their own ageing, followed by the Stephen Sondheim classic “I’m Still Here”, belted out with the composer’s characteristic blend of defiance and poignancy by the formidable Tracie Bennett. Neither number demands an encore, but on each occasion the folk onstage get to take a quick breather while the audience pull ourselves back under control.

Follies (1971) dates – like Company, currently enjoying an acclaimed West End revival – from the period when Sondheim resolved no longer to collaborate on songwriting but to take care of both lyrics and music himself. He takes the opportunity to show off a little with a clutch of Twenties, Thirties and Forties period/genre pastiche numbers for the assorted former showgirls. As they take centre stage one by one, this aspect of the show feels less plot-driven: it’s not unlike a Seventies disaster movie, switching attention between a roster of characters, except that here the approaching catastrophe is no more – and no less – than the inexorably advancing years.

Gradually, however, the focus tightens on a tangled love quartet attempting to straighten out their decisions of thirty years earlier: Sally is resolved that she should have chosen magnetic Ben rather than amiable Buddy, while Ben’s actual wife, Sally’s erstwhile best friend Phyllis, having realised that Ben cares only about himself, has long since gone one better and resolved to care about no-one at all. Janie Dee has the paradoxical gift of making even as abrasive a figure as Phyllis feel engaging to an audience, while even as skilled a musical performer as Joanna Riding still has to measure up to her predecessor in the role of Sally a couple of years ago, Imelda Staunton at the height of her revelatory phase. Alexander Hanson shows a germ of redemption in Ben, while Peter Forbes’ Buddy is the very incarnation of the term “consolation prize”.

Sondheim being Sondheim, of course, nothing is ever that simple, and the middle-aged foursome are literally shadowed onstage by their younger selves, until what has been called their “collective breakdown” cues a climactic sequence that spells out the title’s double meaning: “follies” not only as in the old Weismann show but also in the sense of each individual’s particular foolishness (and including another Sondheim biggie, “Losing My Mind”).

The fundamental success of Cooke and designer Vicki Mortimer lies in conjuring the show’s atmosphere with consummate flair. I suspect even Sondheim himself (and James Goldman, who wrote the book) may not have had fully developed ideas about this simultaneity of real life and showtime opulence, the living and the ghostly, moving between each other with such grace, creating a spectacle which is immediate and also literally haunting.

Written for the Financial Times.