Those who feel that country house opera is in some way not the real thing, just an excuse to dress up and picnic on manicured lawns, should hie to Garsington’s new Die Entführung aus dem Serail with all speed. Yes, the setting is absolutely stunning, people do bring their own food for the hour-and-a-half-long interval, and anyone uncertain of the definition of froideur should try turning up in an ordinary suit instead of black tie. But above and beyond all the frippery, Garsington have come up with a production of this neglected Mozart masterpiece that makes me wonder why it isn’t at least as popular as his Da Ponte operas or Flute.

Of course, it may be performed less often solely because it’s near impossible to find singers who can do it justice. In Amadeus, Peter Shaffer has Salieri deduce from one of Konstanze’s arias that Mozart was sleeping with the singer, and had written her this showy piece as payment in kind. It’s a nice idea, but when you hear the music he gave Blonde and Belmonte, you’re forced to conclude that Mozart either had Herculean (and varied) sexual appetites, or else he just felt like writing that way. Whatever the truth, Garsington have found a glorious Konstanze in Rebecca Nelsen, consistently in the centre of every note during even the most demanding musical acrobatics.

This is all the more impressive since director Daniel Slater is in no mood to let her simply stand there and concentrate on singing. His concept is that the modern equivalent of a sultan with a harem is an über-rich plutocrat, specifically one originally from Moscow who’s bought himself a football team with a predominantly blue strip (a reference that wouldn’t have been lost on David Mellor, who was also in the audience). Having bought himself everything he wants (including, by the end, the Champions League), Selim can’t understand why he can’t buy Konstanze’s love. Thus during her first aria she goes through the rituals expected of a Chelsea lady-who-lunches – tai chi, boxercising, yoga, even a fish pedicure. Her second, after thuggish dark-suited head of security Osmin catches her trying to escape her gilded cage, explains away what Shaffer’s Salieri called “ten minutes of ghastly scales” as her being tortured with electricity – shades of Così fan Tutte.

Osmin, the other standout performance of the night, is taken by Matthew Rose – not the kind of neophyte singer Garsington would normally seek to provide a leg up for, but how many basses are there who can manage Osmin’s low D? Rose shows a great comic talent along with his remarkable voice, equalled only by the cheeky chappie performance of Mark Wilde as Pedrillo, here reimagined as a cockney sports reporter seeking to interview Selim as a pretext for rescuing his love Blonde. She is played by Susanna Andersson, and if the spoken text describes the character as Swedish, it’s presumably only because Andersson is, and they wisely decided to acknowledge the fact rather than trying to disguise her accent. They take the same approach with American tenor Norman Reinhardt as Belmonte, though there’s no disguising that the two of them struggle with comic delivery in the spoken sections – not a skill that’s often required of opera singers. (The spoken text, incidentally, alternates between English and German, with Italian and Spanish eventually also making an appearance, and unlike the singing no translation is provided – a bizarre decision which meant that a lot of what were evidently good jokes were enjoyed by a small section of the audience.)

In any case, Reinhardt brings a strong baritonal quality to Belmonte’s music, and copes ably with the almost parodic excesses of his Act III aria – too many notes indeed. Andersson has a light and pleasing voice, though perhaps her vibrato is a little incessant and could be left as the seasoning rather than the meal itself. Wilde also has a pleasing and clear tone, though his top proved a little unreliable from time to time.

All too often I have to remind myself to say something about a set design so bland I scarcely noticed it, but Francis O’Connor has worked wonders here – the transition between the kitchen and fourth floor of Selim’s mansion in particular is pure genius. In the pit, William Lacey leads the Garsington Opera Orchestra with poise and sensitivity to the often outrageous demands the music makes of the singers. My one quibble would be the chorus. Whilst I like the idea of making them fans of Selim’s football team, they are rather few in number, and it might be a good idea if none of them had to sing from inside large foam rubber heads, diminishing their sound unnecessarily. A must-see.