Quasimodo, King's Head, London

Quasimodo; by lionel Bart; directed by Robert Chevara; with Steven Webb (as Quasimodo) (Francis Loney)

It's a case of Bart – as well as Bats – in the Belfry in Quasimodo.

The legendary Lionel (composer of Oliver!) penned this take on the Hunchback of Notre Dame story in 1965 when his talent was still in very good nick.

But though the music and lyrics were completed, he never finished a satisfactory book and, besides, he was heading towards that two-decade haze of drink and drugs. This was the period when his Kensington home offered, as an ongoing amenity to guests, two massive urns containing, respectively, cocaine and cash. Shakespeare's Timon of Athens would have been an appropriate and stretching subject for him.

The self-dislike and mistrust that often lie behind profligate munificence would have struck several chords with this small, not terribly prepossessing man who could not achieve ease with his homosexuality.

Hence Bart's identification with Hugo's deaf, bell-ringing hunchback. Almost fifty years on from the start of its composition, the piece now receives its much-belated world premiere in a production that has been directed, with an infectiously loving conviction and a powerful cast, by Robert Chevara who has also made additions and adjustments to the book with Chris Bond.

Here, going back to the novel, our hero is a young man, played and sung with a searching sensitivity (child-like but not childish) by Steven Webb. Mercifully binning prosthetics, his deformity is conveyed by just a blotched face and a slight spinal curve. Allowing you to see the underlying handsomeness, this tactic gives paradoxically added weight to one of the musical's themes: the problems we all have in divining each other's souls through the misleading flesh.

The narrative element is a little cheesy (though it won't dissatisfy fans of S & M), but the score, with an excellent reduced orchestration for piano, accordion, and an oily Klezmer-tinged clarinet, has an uplifting directness, characteristically swinging on an axis between the Jewish cantor tradition and the kind of Catholic hymn that sounds like a pub sing-a-long.

The lyrics are, at points, mildly ludicrously top-heavy; by and large, though, the songs each have a strongly distinctive personality – from the madly catchy “Abracadabra” through the belting ballad “So Let It Be” which Zoe George's Esmerelda hits for six, to “Introducing You” in which Quasimodo introduces his bells as if they were individuals. It all adds up to an evening that will give pleasure to a constituency much wider that Bart-buffs and hard-core completists.

To 13 April; 0207 478 0160