Richard Strauss's most popular opera, Der Rosenkavalier, is regularly accused – even by Strauss fans – of suffering from longueurs. The latter part of act two and the first part of act three are usually cited. If it is indeed a classic example of a highlights opera, it was unequivocally the score's choicest sections that made up the second half of Mark Elder's London Symphony Orchestra programme.

There are occasions when this conductor's unbounded enthusiasm rises to an extraordinary level of advocacy for a particular composer, and this was assuredly one of them. Strauss has long been a strong suit for Elder, and – without ever descending into a mere wallowing in the score's sonic gorgeousness – he and his players gave full value to the heady harmonic surges and misty-eyed nostalgia. It was superbly managed from an orchestral point of view, and any other UK ensemble tackling Rosenkavalier in the near future is going to have its work cut out to match it.

Elder's cast was strong. Anne Schwanewilms may lack the sheer opulence of some Strauss sopranos, but her Marschallin possessed poise and allure as well as the deepest sensitivity. Her vital characterisation sustained on her full and fleshy mezzo, Sarah Connolly encompassed perfectly the teenage egotism of Octavian, while Lucy Crowe brought flawless transparency to Sophie's high-flying lines and touching credibility to her essential naivety. If, following these highlights, the audience had been offered the opportunity of hearing the entire opera as an encore, I'm sure they would have jumped at it.

In other circumstances, the alternately energetic and graceful account of Mozart's Prague Symphony that Elder and the players provided in the first half would have left a far stronger impression. Here, though, Strauss's fantasy evocation of the 18th century undoubtedly triumphed over the real thing.