Ariadne auf Naxos is essentially two one-act operas connected by an impending theatrical train wreck. Two music/theatre troupes – one high art and one low – are forced to meld their two pieces on command of their depressive host. The Act 2 results are comic but painless, ending with the transcendent redemption of the title-character, which is when this theatrical hybrid of an opera ultimately morphs into an even less explainable dream world.

Few productions so clearly chart that progression as Philippe Arlaud’s, though it’s bound to generate argument. One of the libretto’s holes is the Composer, who ends Act 1 devastated over the damage done to his work and is never seen again. What becomes of him? Here, he turns up in Act 2, all better now, passing out music to the singers. Nice idea; but it raises more questions than it answers.

The production’s greatest conceptual strength is its Act 2 stage perspective, showing what the singers see as they look out at their refined listeners. The vaudevillians have charming routines, with men in heavily waxed moustaches doing choreographic business with brightly coloured shoes on their hands. Their ringleader, Zerbinetta, sung well by Jane Archibald, is sold short as a mere tart rather than the opera’s down-to-earth voice of reason.

Musical elements are well in hand under Christian Thielemann, though he expands the narrow, chamber-opera-style envelope with higher peaks, especially in the Composer’s Act 1 breakdown, aided by a convincing and tragically extreme Sophie Koch. Her intense characterisation is also a symptom of the production-wide lack of irony. Everything is played as a matter of life and death, which is why lighter moments, such as Renée Fleming’s Act 1 prima donna scenes, feel less convincing.

But once Fleming becomes Ariadne in Act 2, her vocal and theatrical authority are unassailable. It’s great to see her in a role that suits her so comprehensively in a production that fully taps into her charisma. Is an interesting Bacchus too much to hope for? Robert Dean Smith sings well but with little inner motivation. Maybe there’s none to be had. Then again, I thought that about the Act 1 speaking role of the bad-news-bearing Major-Domo, though here, retired tenor Rene Kollo proves me quite wrong.