YOU would hardly expect a composer aged 75 to be writing an opera about sex. But in the free-wheeling moral climate of 1640s Venice, Monteverdi acceded to persuasion with Poppaea, his last hurrah.

There is a certain irony in this keystone of early opera being produced not in the York Early Music Festival, as you might expect, but at Ryedale, even as the two festivals take place simultaneously.

Ryedale thrives on its enterprise and, sure enough, Nina Brazier’s production sold out both its nights. The story, derived from Tacitus, reveals how Nero’s dalliances with Poppaea are ultimately legitimised by a coronation, even as their luckless spouses scuttle around for new partners.

John Warrack’s nimble new translation is not afraid of a touch of demotic, while readily mining elements of comedy.

Old the opera may be, but it was youth to the fore in this startlingly talented cast, with strength in depth throughout.

It was an absolute treat to have Stephanie Williams in the trouser role of Nero. Dressed in a natty black suit, she radiated severity, her strong, true, luminous soprano tinged with enough chest-tone to convey virility. There was also tenderness in her romancing.

Her Poppaea was Elizabeth Holmes, whose light, flexible soprano had an affecting innocence rather than the lasciviousness that history retails.

An exchange of roles with Rebecca van den Berg’s sensual Drusilla (in pursuit of Poppaea’s ex, Ottone, the supple countertenor Ben Williamson) might have suited both.

Maria Ostroukhova’s full-bodied soprano made for a put-upon Ottavia (Nero’s ex), softened by Thomas Morss in drag as her pantomime sidekick.

Rosie Aldridge as Poppaea’s confidante proved a natural comedian and James Fisher’s firm bass suited Seneca well. Caroline Kennedy’s engagingly lively page and Gwilym Bowen’s versatile tenor also caught the ear.

Christopher Glynn, conducting from portative organ, kept remarkable ensemble between cast and the spirited Eboracum Baroque who lined the back of the stage. Dressmaker’s dummies and three moveable platforms were the essentials of Sophie Mosberger’s set; her costumes reflected a variety of modern eras.

But musically this was a triumph, another feather in Ryedale’s operatic cap.