The Fortunes of King Croesus, Grand Theatre, Leeds

An opera in which one of the lead roles is sung by a male soprano (originally a castrato, and not to be confused with a countertenor) would be a daunting prospect for any opera company. First, find your male soprano. For the UK premiere of The Fortunes of King Croesus, by Handel's contemporary, Reinhard Keiser, Opera North has done just that, engaging the American singer Michael Maniaci. An announcement on the opening night that he was suffering from a throat infection didn't augur well. Was it so bad that he was signing, rather than singing, his role?

In fact, in the part of Atis, son of the monarch, Maniaci isn't required to sing for nearly the whole of the first act since his character – unable to speak since birth – communicates through body language. When he is shocked into utterance, at the capture of Croesus, Atis's new-found voice triggers a series of disguises and ruses as he doubles as his own servant and his former, mute self.

Until then, there has been a slow exposition of the tale of love and conquest, from the sophistication of Croesus's court to the devastating battle in which he is captured by his Persian enemies. With the stripping away of the characters' psychological complexities, the political machinations and the romantic alliances, the plot becomes more entertaining. Add Maniaci's entrancing and untrammeled tones in the second and third acts, and the music blossoms, too. He makes the most natural, refined sound, appearing to produce floating high notes effortlessly.

Opera North has not only struck gold with a Baroque rarity, it has assembled exactly the right cast. Paul Nilon is affecting as Croesus, prepared to be burnt alive content in the knowledge that his son speaks.

There are excellent contributions, too, from William Dazeley as the evil Orsanes, John Graham-Hall as a comic bon viveur, Fflur Wyn as Elmira's confidante, and Sarah Pring as a razzled lady-in-waiting. But it is Gillian Keith, as the heroine Elmira, in love with Atis, who – with her luminous sound, exquisite ornamentation and attractive stage presence – captures her character to perfection.

With little sense of time or place, and atmospheric lighting by Thomas C Hase, Tim Albery's inventive staging is effective and stylish. Harry Bicket makes a sound case for Kaiser's score, its lively contrasts and poignant melodies given an authentic airing by the orchestra of Opera North.

In rep to 10 November (0844 848 2700), then touring (www.operanorth.co.uk)