No protests required: Deborah Warner's Fidelio returns to La Scala

When Deborah Warner's production of Fidelio inaugurated the La Scala season in 2014, there were traditional opening night protests outside the theatre to match the revolutionary scenes onstage. If those were dramatic circumstances the production's latest outing felt altogether more run-of-the-mill, with the second performance of the run playing to a half empty theatre on a sticky summer's evening. That, if anything, made it easier to appreciate the merits of this well-constructed production in their own right.

Warner's staging – a sparingly decorated underground lair striped with concrete pillars and filled with details including a clothes line, an ironing board, assorted desks and upturned metal barrels – is suggestive of a modern-day squatters den. Yet here the post-Enlightenment story, which focusses on Leonore's attempts to save Florestan from the grip of his evil captor, Don Pizarro, is given only a vague rooting in time and place. In 2014, Warner challenged audiences to make contemporary connections with places and events emblematic of violations of liberty, including Guantanamo Bay and Isis kidnappings. Today it feels just as relevant. The Prisoners' Chorus, in which inmates savour a fleeting taste of freedom and rally against the gravelike dungeon, could just as easily be victims of the European migrant crisis or family members separated by Donald Trump's 'zero-tolerance' policy.

But in Warner's ultimately moderate reinterpretation it is rightly the musicians that are required to do most of the dramatic legwork. Last time round, Daniel Barenboin's dynamic, rough-and-ready reading made the music splutter, thrust and explode to his every stabbing gesture. The latest conductor Myung-whun Chung's reading contrasted sharply, as he favoured an even, measured sound and spun out the Leonore no. 3 Overture in a gorgeous unbroken arc. A few moments compared unfavourably: the introduction to the Prisoners' Chorus, for example, sounded phlegmatic in contrast with Barenboim's rapturous interpretation. But elsewhere Chung's mastery of orchestral colour and texture came into its own, the brooding introduction to Act 2 making for a harrowingly apocalyptic representation of tyranny.

Strong casting ensured onstage performances provided corresponding drama and finesse. Martin Piskorski brought a strong personality to the young Jaquino, alternating roguish persistence with despondency when his romantic advances are rejected, and Eva Liebau's energetic Marzelline achieved the right mix of innocence and amorous effervescence to give the closing image of her moping when Fidelio's true identity as Leonore is revealed a tragic air. Stephen Milling's excellent Rocco skilfully balanced the lighthearted grumbling with a sense of inner turmoil when the character is called upon to dispatch Fidelio, and the bass' rich, burnished tone was particularly effective in an especially tenebrous rendition of the Act 2 duet "Nur hurtig fort, nur frisch gegraben". Luca Pisaroni made for a convincingly malevolent Don Pizarro. But the standouts were Stuart Skelton's Florestan and Ricarda Merbeth's Leonore. "Doch spur ich nicht sanft sauselende" opened thrillingly when Skelton's powerful, burnished tone shot out of darkness like a thunderbolt in the opening cry of pain. In the remainder of the aria, the Heldentenor communicated steadfast nobility in the face of crushing solitude, before building to an upliftingly sanguine conclusion. Merbeth was no less heroic in the turbulent-cum-devotional "Komm Hoffnung", matching rounded, expressive singing with convincing acting in what was an engaging performance all round. Here were performances to plumb Fidelio's dramatic depths – no offstage protests required.