If you're going to do an opera these days in which the valiant, virtuous crusader vanquishes the evil Mohammedan, it's probably as well not to take it too seriously. Robert Carsen certainly doesn't with his Glyndebourne updating of Handel's Rinaldo, skilfully revived from its 2011 debut by Bruno Ravella, which had the first night audience guffawing as though at the pantomime.

Iestyn Davies as Rinaldo in Rinaldo (Glyndebourne)
Iestyn Davies as Rinaldo in Rinaldo (Glyndebourne)
© Robbie Jack

My colleague Mark Valencia recently called for a stop to productions re-fashioned for the schoolroom, something that's fast becoming another opera cliché, but it does work particularly well here, with the knight Rinaldo re-cast as a bullied schoolboy spinning out a fantasy of adventure and romance.

Every possible school reference is thrown in, mostly of the public school type, which should strike chords with this audience. From my memory, most schoolboys would prefer an encounter behind the bike sheds with Armida's furies, in the form of short-skirted St Trinian's sixth-formers, to Christina Landshamer's prim Hermione Grainger lookalike; but perhaps that's not the case with well-brought-up young gentlemen at a better class of establishment.

The scenario of a valiant schoolboy hero fighting the powers of injustice (his teachers naturally) fits like a glove and there's a further nod towards Harry Potter with the introduction of a firework-spouting magician late in the day. With nimble designs by Gideon Davey, Carsen's antics perhaps lack the pizzazz of a David McVicar extravaganza but it's all very witty and supremely well executed.

The music should, of course, never be upstaged by the concept and one of Handel's most inventive and varied scores has room to breathe in Ottavio Dantone's crisp direction (from the keyboard) of the Orchestra of the Age of Enlightenment. Handel's da capo arias themselves are a perfect fit for the intensive, self-pitying dwelling of an adolescent hero.

'great fun and a fine ending to Glyndebourne's season'

The schoolboy army, with satchel and shining morning face, is appropriately represented vocally by the counter tenors: Iestyn Davies as Rinaldo (proving once more that he's the best of his voice type working in the UK today) and Anthony Roth Costanzo (Eustazio), led by another, the Goffredo of Tim Mead (not sure where his bearded leader fits into the adolescent army – a sympathetic schoolmaster presumably). The quartet of counter tenors is made up by James Laing's crazily hairy magus in the final act.

Christina Landshamer is an endearing Almirena, delivering the work's most famous number (and one of Handel's most inspired) 'Lascia ch'io pianga' with a sincere and demure simplicity. Joshua Hopkins is a strong Argante, the wicked Saracen, and Karina Gauvin a fearsome martinet as the cane-wielding Armida, who brings genuine pathos to the plaintive 'Ah, crudel'.

Needless to say, Carsen's approach won't please the purist (a pretty much uncatered-for minority these days) but it's great fun and a fine ending to Glyndebourne's 80th Festival season. The second performance on 12 August will be presented to a full house of Under 30s who have paid no more than £30 for their tickets – good to see Glyndebourne reaching out in this way. I suspect they'll have a ball.