Turning a 1950s movie into a musical and adding classic Irving Berlin songs could be a recipe for disaster, but (director) Thom Southerland and Paul Alexander's adaptation of The Smallest Show on Earth has fun, style and doesn't take take itself too seriously. It's basically a tale of a young married couple, Matt and Jean Spenser, who inherit a cinema, The Bijou. They attempt to rejuvenate and relaunch the failing venue, despite underhand competition from their close rivals at the glamorous Grand cinema, and are assisted by The Bijou's feisty manageress Mrs Fazackalee and tipsy projectionist Mr Quill. There's a certain charm and warmth about the piece, the actors convince you to care about their characters and the whole evening is peppered with such Irving Berlin classics as 'Blue Skies' and 'Let Yourself Go'. 

The Smallest Show on Earth has a great selection of cooky characters, not least of all those played by show headliners Liza Goddard and Brian Capron. Goddard – best known to me from her numerous Give Us A Clue appearances – can carry a tune quite well, which is handy as her role as Mrs Fazackalee also involves acting as the cinema's resident pianist. Naturally there's a poignant side to the sometimes brash exterior, as she mourns her late husband and wonders if she'll find love again. Brian Capron – aka Mr Hopwood from Grange Hill and the infamous Richard Hillman from Coronation Street – is not an actor I would normally associate with musical theatre, but fortunately his role as the alcohol-soaked projectionist Percy Quill involves more acting than singing and he's perfect for the part. Quill is secretly still in love with his childhood sweetheart (yes, Mrs Fazackalee) and longs for a reunion. 

The Spensers – the couple at the centre of the story – are well portrayed by Haydn Oakley and Laura Pitt-Pulford, who maintain audience interest in their characters throughout the arch of their story. Oakley plays a determined yet often unsuccessful writer who relies on his hard-working wife both financially and emotionally. Pitt-Pulford is always watchable and shows, yet again, why her star is really on the rise in musical theatre. Her songs are perfectly judged and she has real presence in all of her scenes. 

Meanwhile, Sam O'Rourke as Goddard's shy son Tom is secretly in love with Marlene (Christina Bennington, who undergoes a Gypsy Rose Lee style transformation), daughter of the rival cinema owners the Hardcastles. Ricky Butt is clearly in her element as the underhand Ethel Hardcastle, playing various devious tricks, while Matthew Crowe almost stops the show as the Spensers' singing solicitor. 

The inclusion of such timeless Irving Berlin numbers as 'Always' and 'Shaking the Blues Away' actually suits the style of the piece and Lee Proud's choreography pushes the company numbers on against an impressive backdrop (for a touring production) which features Paddington station, the local pub and the cinema. At a time when cinemas, shops and indeed theatres are in competition for loyalty from their consumer base, there is a certain modern resonance to the plot. Sadly, The Smallest Show on Earth didn't deserve what looked like the smallest audience on earth the night I attended, but – like the lead characters – the cast give it their all in the face of adversity and 'sold' the show like true pros. This show might not have set the world of musical theatre alight with enthusiasm, but was a rare curiosity well worth seeing.