There is a tear in the eye of the showgirl in the logo of the National Theatre's production of Follies. It is a tear showing the glitzy make-up starting to run, but it also hints at the emotional depth of this production. In this first fully-staged outing of Stephen Sondheim's musical at the Olivier Theatre since the show's London premiere in 1987, director Dominic Cooke emphasises the dark musical drama of the piece. The opening number sets the scene for the inherent emphasis on characters being constantly haunted by the past – we see their younger selves longingly watching them throughout as they consider 'the roads we didn't take' (also the title of one of Sondheim's numbers from this richest of scores).

Follies was actually inspired by an old black-and-white photograph of Gloria Swanson posing, dressed up to the nines, in the ruins of a half-demolished theatre. The setting is a 1971 reunion at the New York theatre where a group of showgirls have appeared as part of Weisman's Follies many years before. Theatre impresario Dimitri Weisman has gathered the company together for one last time before the theatre is to be knocked down and turned into a parking lot. The opening number is stunningly staged against the magnificent backdrop of Vicki Mortimer's design of a derelict theatre set on stage.

Each number is reinterpreted in a way that makes the piece appear freshly minted even for those Sondheim fans who know it well. Tracie Bennett begins Carlotta Campion's 'I'm still here' while sitting down chatting and then progresses it to a thrilling climax as the lyrics look back at the triumphs and tragedies of her life, referencing the era. Dressed in a bright red dress, the lithe Bennett embodies a character who has got by surviving in life and is currently living with a twenty-something young man.

The plot – what there is of plot for this is a very situational evening with no traditional plot –centres around two couples Sally and Buddy, and Phyllis and Ben. Sally and Phyllis were showgirls back in the day while Buddy and Ben were the stage door johnnies with whom they fell in love. Both got married and by now have fallen out of love with their partners as the years have gone by and this reunion evening brings all the tension and sadness of the past to the surface once more. For Sally was secretly in love with Ben and seeing him again resurfaces all the old feelings.

The musical numbers are beautifully and poignantly staged and interpreted by actors who are really at the top of their game. Imelda Staunton achieves a hat-trick of classic Sondheim roles, having previously appeared in Sweeney Todd and Gypsy. She is not an obvious choice vocally for soprano Sally but she has developed so much vocally over the past few years and sings Sally with a real and moving yearning. The ‘Too many mornings’ duet with Philip Quast’s Ben is heartbreaking as they both realise how quickly their lives have slipped away, while her earlier solo ‘In Buddy’s eyes’ gives a real sense that the character is fooling yourself and is disillusioned. Janie Dee is well cast as Phyllis who has made such an effort to be good enough for her husband while being destroyed inside by his infidelity – ‘Could I leave you?’ is a masterclass of spiteful wit.

The other showgirls are no less an important part of the plot as they recall their moment in the spotlight. The most moving of these is Dame Josephine Barstow’s ‘One more kiss’ with the ghost of a younger self singing with her. Di Botcher puts in an amusing turn as Hattie Walker – a woman who has had five husbands – and sings an initially understated 'Broadway baby'. Dawn Hope as Stella leads the ‘Who's that woman’ number, stunningly choreographed by Bill Deamer where the ladies do an old number once again and gradually merge with their younger selves.

Follies is a musical that becomes more poignant the older you get. This version also uses the original Broadway version rather than the original London version which changed some of the numbers and gave a more optimistic ending to this ever hopeful of a hopeless show. By the end of the evening my arms and shoulders are aching from the strength of my clapping every number and my legs aching from sitting for two and a quarter hours without an interval which cranked up the tension in the audience and in the story even more. But it was worth it to see this once-in-a-lifetime production and memories of this Follies will haunt me for a long time. It’s impossible to get tickets for the rest of the sold-out run but Follies will be broadcast by NT Live on 16 November.