Strauss defined Die Liebe der Danae, his penultimate opera, as "a light-hearted mythology", an Offenbachian romp about Olympian sybarites. Jupiter entices Danae with a golden shower, then - to delude the proprietorial Juno - woos her with the connivance of his deputy Midas, a lowly muleteer to whom he has temporarily awarded the golden touch. Danae infuriates Jupiter by preferring Midas, even when the god deprives him of his power to gild the world. The sexual farce gradually darkens into a fable about the moral and emotional gulf between gods and mortals. Wotan in Wagner's Ring cycle angrily sentences the errant Brunnhilde to share the fate of his human subjects; here, Jupiter, sadder and wiser, recognises that these inferior beings can experience a love that is unavailable to feckless deities.
In this classical comedy, Strauss struggled to deal with a contemporary tragedy. He completed the score in 1940, cannily dedicating it to Goering's croney Heinz Tietjen in the hope that this act of ingratiation would exempt his family from Nazi racial laws (Strauss's daughter-in-law was Jewish). But he refused to permit performances of the work, insisting that it must wait to be staged after the war, even if he were no longer alive to see it. Although he agreed eventually to a production at the Salzburg Festival in 1944, Hitler's declaration of "total war" closed down all the theatres in the Reich before it could open. A dress rehearsal went ahead, as a personal concession to Strauss; the premiere was postponed until 1952, four years after his death.
Now, 50 years later, Salzburg has revived Die Liebe der Danae and revealed it to be a masterpiece. Gunter Kramer's production ingeniously employs the opera to narrate the half-century of German history since that aborted staging in 1944. It begins during the apocalypse. The bankrupt Pollux cowers in a blitzed palace beneath an emblematic broken eagle, like Hitler huddling in his bunker with the autograph score of Gotterdammerung. The arrival of Midas prompts a financial recovery, ushering in the "economic miracle" of the Fifties. Selling off his daughter Danae, Pollux scribbles a graph of instant enrichment on a wall-chart. Affluence - described and denounced by Hugo von Hofmannsthal as a "Geldwelt", in a letter projected on to the curtain between the first and second acts - turns earth into a tacky, mercenary heaven. Jupiter swans about in bathrobe, panama hat and patent leather slippers, like Onassis or Orson Welles's Mr Arkadin: gods nowadays are celebrities, promoted to supernatural status by their fame and money.
The third act, with its recriminations and renunciations, arrives in the uncertain present. The sensual and gaudy stage pictures of the designer Gisbert Jakel disappear behind layers of black, muffling drapes. Almost invisible in the gloom, Jupiter stands on the forestage; Danae, listening to his entreaties, peers through an opening in the curtains. After rejecting him, she steps backwards, and the curtains part to reveal the reality she now happily inhabits. She is in an eyrie high above Salzburg itself, watching the mountains inflamed by a sunset as the orchestra plays one of Strauss's heart-breaking elegiac benedictions. Jupiter - who is not only Wotan but Hitler, occupying his aquiline fortress across from the Untersberg - follows her, huddling in a deckchair like a patient at a sanatorium, fussed over by Juno. Danae therefore steps down from this enskied plateau, and retreats to a world he cannot enter. The cloth on which the mountains were painted rolls up, and a door in the back wall of the theatre swings wide open. She strides out on to an actual Salzburg street, where, naturally, it is raining, and disappears into the muddle of weeping umbrellas - anonymous, doomed to die, but gratefully, radiantly alive for the time being.
As Danae, Deborah Voigt is ardent and forceful, though she lacks the erotic rapture that Leonie Rysanek, who sang the role at Covent Garden in 1953, brought to her final, self-justifying cries of "Siehe, ich liebe!" The role of Jupiter is throat-tearingly strenuous: anyone who can sing it elects himself to Olympus. Franz Grundheber heroically surmounts the thunderous orchestra, and charts the god's change from cynicism to remorse with rare psychological insight.
The conductor is Fabio Luisi, replacing Giuseppe Sinopoli (who died) and Christoph von Dohnanyi (who cancelled). Thanks to him, the Dresden Staatskapelle makes the alchemical magic of Midas sound truthful not tawdry. After the recent floods, the river that gushes through Salzburg looked murky and treacherous, with collapsed embankments and toppled trees flung against the foundations of bridges. But what I heard overflowing from the orchestra pit in the Kleines Festspielhaus was a river of molten gold.