As I left Holland Park after last night’s Cavalleria Rusticana and Pagliacci, I found myself wondering what they’d put in the orchestra’s cups of tea at the interval. Or, perhaps, what was it that conductor Stuart Stratford said to them. Because I don’t think I’ve ever seen an opera performance that was (to borrow a phrase from football) such a game of two halves: a lacklustre Cavalleria followed by a thoroughly entertaining Pagliacci.

The “Cav and Pag” double bill is a classic one because the two operas are similar not just on the surface but in depth: both embody a contrast between light and darkness. For Cavalleria Rusticana, the light comes from the hard Sicilian sun and the simple joys of the Easter celebrations; for Pagliacci, it comes from stage lights, with all the fun of the fair. The darkness is the same: the visceral fear of concealed adultery and the black jealousy that follows it, the more terrifying in the backward rural Italian South (as the Tuscan Mascagni and the Naples-educated Leoncavallo would have seen it).

But last night served to highlight their musical differences. The music of Cavalleria Rusticana sweeps in grand arcs, much in the fashion of Puccini, taking its colour from lilt and phrasing. To my ears, the City of London Sinfonia failed to bring this across: I heard too many small timing inaccuracies – nothing you’d describe as a fluff, just the players not reaching that ultimate level of perfect togetherness – and I didn’t hear enough togetherness of feel for phrasing or enough individual brilliance in solo wind or harp passages. It seemed to drag down the singers: Gweneth-Ann Jeffers as Santuzza sang her heart out, but even her ample strength and warmth of voice seemed somewhat detached from the orchestra. Peter Auty was a rather ineffectual Turiddu, which, to be fair, is very much in the nature of the character, while Stephen Gadd’s Alfio had too much of the smooth professional and not enough of the rough and tough, windswept character who dominates the stage whenever he’s on it. Gadd didn’t summon up the required commanding tone of voice and wasn’t helped by being dressed in a smart business suit rather than something more earthy. The settings and costumes were well enough made, with giant stacks of Sicilian orange crates placing the action in its setting, but also contributed to the downbeat feel: those high piles of dark brown negated the contrast of external light and inner darkness.

But after the interval, we were in a different world. The orchestra seemed fully attuned to the score of Pagliacci, which is far more laden with short individual snatches of melody: their accenting became more marked and everything tightened up. Stephen Gadd seemed to respond: as he changed on-stage from his Alfio costume into that of the hunchbacked clown Tonio, he gave us a powerful and nuanced rendering of the prologue. It’s a marvellous passage which serves as a statement of creed for the verismo movement, and Gadd extracted its full force. As the orchestra improved, so did Stephen Barlow’s staging, bringing out the contrast between the bright, sunny disposition of the theatregoers with the dark goings on behind the scenes. The acting was excellent, particularly Julia Sporsén as the adulterous wife Nedda, and as we arrived at the play-within-a-play, the blurring of commedia dell’arte make-believe and reality came across brilliantly. It’s a startling scene in which all the players are in character until Canio becomes overcome by his jealousy and starts to sing about real life in earnest, but since the others are still in character, confusion reigns in the audience. This crucial scene was performed with total conviction.

The singing from the chorus was up to a high standard, as were the various duets and arioso passages from all the principals; Chang-Han Lim was notably melodious and ardent as Nedda’s lover Silvio. But I was disappointed by the opera’s big number, Vesti la giubba. Peter Auty was technically up to the mark, but for the full effect, the tenor playing Canio has to disintegrate in front of your eyes as the man finds it near-impossible to face going on stage with the woman that he now knows to be unfaithful to him. It’s an aria that can have immense power – the power to make or break an evening – but it needs far more drama than Auty was able to impart.

In sum, a very mixed evening. Both of these operas have a great deal more subtlety in them than is apparent at the surface, and while much of this was brought out in both the music and acting of Pagliacci, I felt the performance substantially missed the mark in Cavalleria Rusticana. I’m left to muse on how that can happen on an evening where the orchestra, chorus, conductor, director and most of the singers are the same – one of opera’s many mysteries, I suppose.