Buddy – the show about Buddy Holly celebrating its 30th year – is a foot-stomping, character-enlightening, feel-good/feel-sad extravaganza that has audiences dancing in the aisles. How infinitely sad (and yet how wonderful, too) to think this musical has lived longer than the mould-breaking star it celebrates, says Katie Jarvis

There's this terrific scene (actually, there are loads of terrific scenes) some way into the first half of Buddy.

We're in Harlem, New York, at the Apollo Theatre, where a frisson is shivering through the excited audience; Buddy Holly (three records riding the charts high) and the Crickets are about to appear. It's their first time in the Big Apple.

But we're not in the audience; we're backstage, where an interloper has managed to penetrate the non-security of this legendary music hall. It's Hipockets Duncan (the absolutely marvellous Harry Boyd), DJ on Texan radio show KDAV, who's desperate to see the rock star he once knew as a humble roof-tiler; the rock star he tried to promote by giving him air-time when few others were interested; the rock star he tried to persuade to play country and western twang when all Buddy wanted was to go wild with Rip It Up.

The two black women Hipockets bumps onto, in his illicit backstage foray, burst into peals of laughter when he tells them who he's here to see. "Buddy?" they roar! He won't see you! Finally, the women collect themselves enough to explain why. He won't see you!... Not because Buddy Holly has become such a big star. Not because Hipockets Duncan is a small-town DJ.

But because Hipockets is WHITE! And everyone who hears Buddy's music knows he must be a black man! This is one of the things I loved about Buddy. It's a musical, yes, full of numbers - Words of Love; True Love Ways; Raining in My Heart - that you'd almost forgotten were pure gold. But it's also a window into an alien world. A world of the 50s where Buddy readily agrees to give 10 percent of all he earns to his church. A world which listens to music on the wireless but rarely sees the stars it idolises. A world where Buddy is ordered to take off his glasses when he's onstage - and a world he changes by refusing: "Buddy Holly does things his way!" (In fact, he thinks, he might even get him a real thick pair.) And it's a world where he meets a girl working behind the reception desk in his record company, and instantly tells her he's going to marry her. Which he does. True Love Ways.

Sorry to sound like everyone's grandmother, but what a clean-cut, clean-living decent boy he was. So when the end comes - and, if this is a spoiler, then don't watch Titanic either - it's not only moving; it's a shock. For this star who changed the world was famous for less than two years. Two years!

And when he died, in the plane crash that should never have happened, he was 22 years old. 22 years old! (And how beautifully, movingly, that death is portrayed on stage.) Two years. Yet Bob Dylan adored him (as the Everyman programme quotes, 'When I was 16 or 17, I went to see Buddy Holly play and I was three feet away from him… and he LOOKED at me'. Myopic John Lennon said Buddy made it OK to wear glasses. McCartney (who went on to buy the rights to Buddy's back catalogue) said there wouldn't have been any Beatles had it not been for the Crickets.

But.

If you think this is a play that's funny (it is), emotional (it is), enlightening (it is) and full of engrossing true-life plot (it is); a play about a nobody lad from Texas who changed the world (it is). Then RIP IT UP! Because it's also a FABULOUS night of music. Cast, you were wonderful. AJ Jenks as Buddy (who'd clearly studied every existing film-clip) has got to have a stand-out shout-out. But, everyone, you were marvellous, multi-talented, perfect.

The man died on February 3, 1959.

The music never will.

The Everyman Theatre is at Regent Street, Cheltenham, Gloucestershire GL50 1HQ, box office 01242 572573.