If you find, during an opera performance, that you’re paying more attention to what’s happening in the pit than to the action on stage, it’s normally down to one of two things: the singers and production are particularly awful, or the orchestra is particularly exceptional. In the case of Sunday’s Glyndebourne performance of Rinaldo, it was the latter.

I’d always known that the Orchestra of the Age of Enlightenment were one of the finest period bands around. But on Sunday, under the energetic leadership of Ottavio Dantone, I realised just how good they really are. It wasn’t just their supreme musicianship, in both accompanying and soloist roles, that impressed – although I have to mention here the recorder trio during Almirena’s opening aria, particularly the sopranino player who fairly flew around her instrument. Nor was it just their ability to play so utterly in synchronicity that the violin section positively sounded as one. And nor was it just Elizabeth Kenny, whose vivacious theorbo playing constantly drew my ear. No, it was more than that: a beautifully understated, refined sound, always in tune, always just right dynamically, always giving what was called for at the right moment. And under Dantone, they seemed injected by real energy and commitment – cue admiring glances among themselves during the maestro’s flamboyant harpsichord extemporisations.

On stage, it was rather more varied. Sonia Prina’s Rinaldo was convincing, vocally and physically – her manly demeanour was unwavering! – but I didn’t much care for the timbre of her voice. Sandrine Piau’s replacement, Anett Fritsch, was a touching Almirena, her “Lascia ch’io pianga” a real highlight. And I particularly enjoyed Luca Pisaroni’s menacing Argante, Tim Mead’s Eustazio and Varduhi Abrahamyan’s Goffredo. The new production by Robert Carsen set the opera in a modern-day classroom, which on the whole worked pretty well. It was a clever idea to have the heroes advancing towards the enemy through a chemistry laboratory filled with Bunsen burners complete with firework explosions, and the final battle – played out in the school playground as a football match – was hilarious for all the right reasons.

Other scenes seemed static in comparison, though, and I longed for some visual colour amid all the grey school uniforms. But during any dull moment, I only had to look to the pit for excitement aplenty – and, judging from the audience’s reaction when the orchestra rose to their feet at the end, I wasn’t alone in thinking that the orchestra, not the singers, were the stars of this show.