Twogreat landmark works in the history of 20th-century music have delighted audiences as WNO continues its annual summer visit to the Apollo, writes Chris Gray.

On Wednesday, a full house relished the heart-tugging emotion, the sparkling comedy and the gloriously melodic waltzes of Richard Strauss's Der Rosenkavalier, which is performed again tomorrow night.

Then last night, we shivered at Henry James's spine-tingling tale of innocence corrupted, The Turn of the Screw, in Benjamin Britten's captivating opera of 1954. Though it runs for more than four hours, Der Rosankavalier offers such undiluted pleasure that time passes almost without one's noticing.

A memorable feature of this production is the performance of the young American Daniel Sumegi, in his British debut, as Baron Ochs. The determination of this thick-skinned aristocrat to wed a 15-year-old heiress with the help of her social climbing dad (Christopher Purves) provides the mainspring of the plot.

Though initially keen on the idea, Sophie (brilliantly sung by Natalie Christie) quickly changes her mind when she meets the boorish braggart, switching her affections to his good-looking emissary in love, Octavian. That this role is played, in the fashion of more than a century earlier, by a woman soprano is entirely in keeping with the opera's setting in 1745 Vienna (even if those famous waltzes confusingly aren't).

Moreover it gives the opportunity for some glorious duets between 'him' (Katarina Karneus) and the lovely princess Marie-Therese (Deborah Riedel) whose devoted toy boy he is.

Last night, with the admirable conductor Carlo Rizzi again in charge, much more modest orchestral resources were employed to frighten us out of our wits in The Turn of the Screw. Taut and tingly, the music perfectly reflects the tensions on the stage as we watch a caring Governess (Janice Watson) protect her two young charges (Gregory Monk and Yvette Bonner) from the malign influence of two ghosts.

Quite what the hateful Peter Quint (Paul Nilon) and his governess lover Miss Jessel (Geraldine McGreevey) had done, and still want to do, to the children is never made clear but it certainly isn't anything nice.

Sated in murky blackness with magical lighting (Paul Pyant), John Crowley's production is another WNO triumph.