Few stories better illustrate the pitfalls and pain of show-business life than that of Judy Garland – which is why it is such a familiar one. A spoilt and cosseted child star, she became a queen of the screen yet never really believed in her looks or talent. Seeking solace in a series of doomed relationships, in alcohol and pills, she died of an accidental drugs overdose at 48.

She was dead, but not forgotten. As the final line spoken in Peter Quilton’s End of the Rainbow expresses it: “Immortality might make up for everything.” Today, 41 years after her death in London – appropriately for a gay icon it coincided with the Stonewall riots in the US – her name remains well-known around the world, her films and recordings savoured by a new generation of admirers.

For these, surely, this excellent play with music, first seen in 2005, is a show made in heaven. Those so far untouched by the Garland myth are just as likely to be captivated by the piece, not least for the ready wit it contains. Its revival, under director Terry Johnson, as the first offering in the Royal & Derngate’s Addicted to You season, is a major theatrical event.

The wit might be surprising, since the play concerns the last months of the star’s life when, struggling to keep her head above water, she arrives in London for a punishing series of concerts at the Talk of the Town. With her in her suite at a supersmart hotel (sumptuously recreated by designer William Dudley) are her latest squeeze, soon to be husband number five, Mickey Deanes, a disco owner many years her junior, and her Scots-born accompanist who shares the devotion of so many gays for the charismatic singer.

Both parts have been superbly cast, with the exceptionally handsome and talented Stephen Hagan as Mickey and the excellent Hilton McCrae – who also plays piano with a five-strong on-stage band – both showing real affection for the doomed chanteuse in their different ways. And, indeed, behind the tantrums and the benders, we can see there is much to admire.

Quilter’s considerable achievement is to allow his Judy – one suspects it is truly the Judy – to see the funny side of her plight. A good instance comes with the hilarious dialogue that follows her guzzling of pills filched from a bottle in Anthony’s briefcase. He explains they were mange pills intended for his sister’s spaniel. Garland happily impersonates a playful hound for the next few minutes.

And so to the very best thing about this revival, the wonderful performance of Tracie Bennett. Wraith thin and looking uncannily like the star, she acts and sings with a passion, power and utter commitment that make one wonder – as Garland wondered at The Talk of the Town – how she will ever complete the run. After previous awards for her work in Hairspray and La Cage aux Folles, she is surely in line for another. Don’t miss the chance to see her.

Royal & Derngate, until February 20. Tel: 01604 624811 (www.royalandderngate.co.uk).