Not quite a musical, but somewhat more than a concert, song cycle The Distance You Have Come brings together some of the greatest hits from Scott Alan’s star-spangled songwriting career, performed by an equally glittering cast of West End talent. On paper, it’s a musical theatre fan’s dream. In practice, a flimsy story and over-emotional first act hold an otherwise excellent show back from quite hitting all the highs we might expect.

The plot that links all the songs together is based around six people, whose lives intersect in different ways as they each walk their own path through the ups and downs of life. While Joe (Dean John-Wilson) battles addiction and heartbreak, new lovers Samuel (Adrian Hansel) and Brian (Andy Coxon) plan their future as parents; Anna (Jodie Jacobs) and Laura (Alexia Khadime) are coming to terms with their recent break-up, as Maisey (Emma Hatton) is struggling to get her big break in the theatre.

Both performances and music are as top-notch as you’d expect given the credentials; there’s no denying the sensational talent of the cast and musicians, or the poignant beauty of the songs. This is music from which a good vocalist can wring every last drop of emotion, and these six performers do it so effectively that in Act 1 it all gets a bit much. With a couple of welcome exceptions – most notably the fabulous Jodie Jacobs and her comedy number, His Name – the tone throughout the first hour of the show remains much the same, and the songs begin to run together as we move from one desperate situation to another, with very little time to pause for reflection (or even applaud) in between.

It’s therefore a relief that the mood lifts significantly after the interval, when the plot threads – which until that point have been proving difficult to reconcile – finally come together. As the characters begin to make connections and find their way out of the darkness, there’s a lot more hope and humour to be found on all sides, and the show ultimately ends on a joyful high with the infectiously uplifting title number.

The simple staging of the show has most of the action taking place in a park, which provides a convenient central location for the characters to run into each other, or simply meander past as they go about their lives. Unfortunately, because it’s in the round, the actors inevitably have to turn their backs on parts of the audience, and this causes some problematic acoustic issues – particularly in the group numbers, when it can be impossible to hear what someone facing away on the other side of the stage is singing about.

As a showcase of Scott Alan’s work, The Distance You Have Come is a hit; for existing fans it’s a celebration, for newcomers a pleasant introduction that will no doubt have you heading for Spotify the moment the show’s over. The cast, too, are superb, conveying all the joy, heartbreak, frustration and emotional fragility of their characters whilst simultaneously blowing the audience away with some stunning vocals. Setting it to a story – also written and directed by Alan – actually proves a bit of a distraction from all this excellence, and you get the feeling the whole show might have worked a bit better in a concert format. Nevertheless, if you want to hear some beautiful songs, exquisitely performed, it’s certainly worth travelling some distance to experience.