Curly wasn’t curly and the surrey was just a fringe on a handcart, but there was little else to complain about in Rachel Kavanaugh’s super-semi-staged Oklahoma! at the BBC Proms. The John Wilson Orchestra may have been the headliners but a sharp, crisp production and a terrific cast made this a thoroughgoing theatrical experience on every level. All three hours of it.

In his typically scrupulous fashion, John Wilson has compiled an ultra-complete version of Rodgers and Hammerstein’s first collaboration. With every word and every note of the full score present and correct, a musical that is high on tension but low on action needs immaculate presentation if it’s not to feel leaden – and that is what we got. Wilson's 37 musicians led the way with an overture of spry delights, daringly fast yet anything but furious and seasoned with the merest hint of 1940s Broadway-style portamenti. Perhaps the violins were a mite over-dominant, but with fiddlers this good who’s complaining?

There were two performances on the day, the second of them broadcast live by BBC Radio 3 and televised after a short delay on BBC4. This review, though, addresses the matinée of a few hours earlier – Prom 34 – a fact that might explain the hint of tightness during the first half-hour, especially from Nathaniel Hackmann as Curly. A TV viewing of Prom 35 suggests that had vanished by the evening, but in the afternoon it wasn't until Robert Fairchild’s rousing Will Parker and choreographer Alistair David’s dancing cowhands hoofed their paean to Kansas City that things loosened up.

Hackmann, a stocky baritone with the tenderest of timbres, was like a reincarnation of Alfred Drake, the original Curly. There is no greater compliment. If he could have found a degree more subtext in some of his songs he would have been nigh on perfect. In "People Will Say We’re In Love" for instance, a duet about a love that has not yet dared to speak its name, none of the ache and hope in the line “Your hand feels so grand in mine” came through.

The talented American fared better in his dark two-hander with the villainous Jud Fry, but there he was up against David Seadon-Young, an astounding antagonist. Neither as glum as Rod Steiger in the film nor as black-hearted as Shuler Hensley in Trevor Nunn’s NT version, Seadon-Young’s Jud cut a poorly-co-ordinated, shuffling figure, slow-witted and pathetic and all the more dangerous for it. It was a subtly conceived, magnetically sustained full-body performance, light years away from his day job on An American in Paris.

Lizzy Connolly delivered the damaged goods as Ado Annie, Marcus Brigstocke successfully channelled Jimmy Durante as Ali Hakim and Belinda Lang squawked like one of her farmyard chickens as the matriarchal Aunt Eller. All three were a bit shouty, and the women’s accents came and went, but they certainly animated their scenes. As for Scarlett Strallen as Laurey, this consummate young musical actress shone as brightly as Mary Poppins, her signature role, albeit with a pronounced warble above the stave that some will have relished more than I. (It may have been the tinnily resonant amplification in the hall that made this more intrusive when heard live than it was in the broadcast versions.) Yet Strallen is as triple-threat as they come, and her dancing in the "Out Of My Dreams" ballet had physical purity and grace.

Incidentally, there was no programme credit for Robert Russell Bennett, the original 1943 orchestrator whose contributions are so much a part of the Oklahoma! experience. It would be interesting to know if this was by accident or design; either way, the omission is surprising given the otherwise meticulous nature of this triumphant undertaking.

****1