Aware her teenage lover will inevitably leave her for a younger woman, the Marschallin muses that time trickles like sand through an hourglass, flowing ceaselessly. At night she stops all the clocks, yet accepts time is not to be feared. Everything comes to an end. The trick is knowing when to bow out gracefully. Ultimately, the Marschallin bestows her blessing on Octavian and Sophie and leaves the youngsters to it. Likewise, Renée Fleming has decided the time is right to bow out gracefully from the operatic stage, choosing her signature role to bid the fondest of farewells to London.

Arguably, her departure comes too soon. Fleming's soprano may now be tinged with paler gold, but it retains much of its lustre. Silky elisions between notes – one of her familiar traits – sound as sexy as ever and her feathery G on “die silberne Ros'n” at the end of Act I was exquisite. She is incredibly responsive to text and in the final scene looks a million dollars in glittering black. Even the manner of her curtain call was perfection: despite the flower throw (a rarity at Covent Garden these days) there was no grandstanding, just a simple curtsey, applause for the orchestra, accepting her bouquet then joining the line-up so as not to distract focus from Alice Coote about to take her call as Octavian. Sheer class.

Robert Carsen's new production of Der Rosenkavalier is a great vehicle for Fleming which transfers – with, on paper, a stronger cast – to the Met next spring. In yet another operatic updating to 'the time of composition', he moves the action from the 1740s to Vienna in 1911. Paul Steinberg's grand bedroom, decorated with red flock wallpaper – with matching livery for the Marschallin's footmen – dwarfs the cast. Sets of double doors open to reveal not one, but three more rooms. Carsen loves a giant bed (Poppea, Falstaff, A Midsummer Night's Dream) and we get a pair of them here – one in the Marschallin's bedroom, beneath a portrait of her husband, the Feldmarschall, in military uniform, the other is a drop-down whopper in Act III which takes even Baron Ochs by surprise. The first act is packed with delicious detail: the white-suited tenor (a full-throated Giorgio Berrugi) signs his latest gramophone record; oily schemers Valzacchi and Annina (the excellent Wolfgang Ablinger-Sperrhacke and Helene Schneiderman) plot; borzois, boxers and a bulldog jostle for attention.

The von Faninals' home is a study in over the top taste with its dizzying floor, Greek frieze and smoking howitzers displayed in the lobby of this arms dealer into which Octavian delivers the blingiest of silver roses, worthy of Liberace's Christmas tree. Act III feels like a misfire, relocating from an inn to a gaudy, bawdy brothel where Octavian's “Mariandel” clumsily seduces an increasingly unnerved Baron Ochs. Would the Marschallin be seen dead visiting a brothel?

Matthew Rose's splendid Ochs is young, boorish and swaggering... but so is Alice Coote's Octavian and here's a problem. I'm not sure what the Marschallin sees in this 'Quinquin' who is cast in the same petulant mould as her country cousin. In addition, Coote was vocally ungainly on opening night with a cloying lower register that lacked appeal. She played much of the comedy well though, especially when trying to square up to Ochs, looking him firmly in the chest. Rose's beautiful bass with its sepulchral bottom notes didn't disguise Ochs' nasty nature, especially in Act II where this repulsive bear of a baron gropes his bride-to-be and flicks cigarette ash into the pit.

Sophie Bevan played her namesake as a flighty girl who knows exactly what she wants. In the Presentation of the Rose, her terrific pianissimo on “Like heavenly, unearthly roses” was one of those moments when time stands still, Carsen's fondness for blue moonlight to freeze key moments paying off well. Who could resist this girl's advances? Among the rest of the cast, Jochen Schmeckenbecher stood out as a hectoring, splenetic Faninal.

In the pit, Andris Nelsons set off rather excitably, risking premature ejaculation in Strauss' erotic romp before settling down somewhat. The ROH brass responded vividly, but several times during the evening the orchestra risked drowning the singers, nowhere more so than the orgasmic climax of the trio, where voices were sometimes obliterated. After that gorgeous trio and the sublime duet for Sophie and Octavian, Fleming's Marschallin – with a wicked twinkle in her eye – allows herself to be escorted away by the dashing young police commissioner! Perhaps the clocks can be stopped after all...