All are in top form for "Lohengrin, " whose orchestral prelude and choral passages are the musical crux of any performance.

WSJ: Review: High Note in Berlin | 'Lohengrin' at Deutsche Oper

Her repertoire also included art songs and arias, the most ambitious of which is probably "Elsa's Dream" from Wagner's opera Lohengrin.

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Klaus Florian Vogt, who replaced Marco Jentzsch as Lohengrin at the last minute, has sung the role everywhere from New York's Metropolitan Opera to Bayreuth's Festspielhaus.

WSJ: Review: High Note in Berlin | 'Lohengrin' at Deutsche Oper

ExxonMobil, Chevron, Shell and other corporations doing business in dangerous parts of the world will certainly be pulling for the legal Lohengrin to disappear into the mists again.

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Created by A-lister Kasper Holten, the Dane known for his Copenhagen Ring cycle and now director of opera of London's Royal Opera House, this "Lohengrin, " which is set in the Middle Ages, actually has principals dressed in medieval-looking costumes.

WSJ: Review: High Note in Berlin | 'Lohengrin' at Deutsche Oper

On May 19 at Carnegie Hall, Mr. Levine will conduct the Met Orchestra in a program that will include the prelude to Act I of Wagner's "Lohengrin, " Beethoven's Piano Concerto No. 4, featuring piano soloist Evgeny Kissin, and Schubert's Symphony No. 9.

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In 2016, she is scheduled to sing Elsa in "Lohengrin" in Dresden under the baton of Christian Thielemann, whose "demonic energy" she likens to that of Valery Gergiev, the Russian conductor who has played paterfamilias to a generation of singers from the former Soviet Union, including Ms. Netrebko.

WSJ: Anna Netrebko | So Long, Ing��nues | Cultural Conversation by David Mermelstein