Ariadne Auf Naxos, Royal Opera House, London

It's still one of the most expensive scenic tricks the Royal Opera wheels out. In the opening moments of Christof Loy's staging of Strauss's Ariadne auf Naxos, designer Herbert Murauer spirits us to the lobby of some glamorous art deco apartment building, but instead of taking the elevator to the lavish penthouse where our rich patron awaits, we all descend – or rather the entire set ascends – to reveal the dingy "backstage" below stairs.

Unfortunately that audacious scenic coup makes for a long interval. But since Ariadne begins as the ultimate backstage opera, expensive jokes are the order of the day. And with a classy cast making its presence felt early and Mark Elder (now Sir) busily building impetus through this fraught three-quarters of an hour, the essence of Strauss and his librettist Hugo von Hofmannsthal's delicious conceit is well established.

Dominating the Prologue is the Music Master – a hypertensive Thomas Allen with wonderfully incisive diction – and his "gifted" pupil, The Composer, sung with heated ardour and storming top notes by the American mezzo Kristine Jepson. Her/His little scene with Zerbinetta (Gillian Keith), the eye-candy of the "comedy" act, beautifully sets up the central idea of the Opera proper that the comedians and the tragedians can and do co-exist.

In the Opera proper, Murauer's designs again score, the exotic murals of an elaborate room serving as Ariadne's desert island, candlelight lending magic. The first intrusion of the vaudevillians into Ariadne's rarefied "inner-world" is delicious, their alienation pointed up in the costumes – a kilt, combats, bike leathers.

Elder's conducting comes into its own here with the intimacy of string playing at once glowing and intense. But would that that warmth extended to the sound his Ariadne makes. While Deborah Voigt, now fitting in that little black dress, can rattle the rafters with her money notes, the beauty and bloom is wanting. I can remember a time when she would never have so badly dropped a stitch in one of her aria's key phrases.

Her Bacchus – Robert Dean Smith – is, by contrast, wonderfully secure, conserving the lyricism where many merely manage the strenuous heroics. And Keith's Zerbinetta really gives dramatic purpose to her high-popping coloratura tirade against faithless men. The pathos of her final line, "When a new god arrives we surrender", really rings true for once.

To 1 July (020-7304 4000)