Time ticks its inexorable tock from the very first lines of Der Rosenkavalier: “How you were! How you are!” In the contrast between those two tenses lies the tension of the entire opera. The present is fast becoming the past, taking with it people and attachments held dear, and the future is unclear. And in the contrast between those two statements lies also the source of the valedictory air which filled Symphony Hall as the Boston Symphony and Andris Nelsons performed a semi-staged Der Rosenkavalier with Renée Fleming as the Marschallin and Susan Graham pairing with her one last time to sing Octavian, after retiring the role seven years ago.

Time has been kind to both women since they first sang together in this opera nearly 17 years ago; how they were and how they are now are not substantially different. Both voices have darkened, both have lost much of the sheen of youth, but their familiarity with their roles and each other more than compensate for what time has pocketed. Fleming had problems consistently being heard but she can still spin and float a phrase and remains in the moment dramatically, having internalized the words and the music to such an extent that she simply is the Marschallin. Graham might sound older, but she can still look the adolescent male, plus her comic timing is flawless. The ease of interplay, which years of singing these roles together brought to the evening, deepened the emotional import of their characters’ eventual parting.

Until shortly before its completion, the working title of Der Rosenkavalier was Ochs auf Lerchenau, literally “The Ox in the Lark-Field” or more colloquially, “The Bull in the China Shop”. The nomen omen pun may have been discarded, but Baron Ochs remains central to the opera. Given a mediocre singer who just barks and bloviates, Der Rosenkavalier can be a penance. Given a Franz Hawlata, who sings the role and acts with panache, you have an Ochs who is, yes, a clod and a boor, but an endearingly clueless one. His miscalculations are the fruit of his boundless and often misdirected enthusiasm, an infectious joie de vivre appealing rather than repelling. It would be no exaggeration to say Hawlata stole the show, an act of grand larceny made all the more remarkable by the strong cast which shared the stage.

Erin Morley’s bel canto past shows in her clear, tempered soprano, her breath control, and in the ease with which she unfurls Sophie’s long, soaring lines. She and Graham blended meltingly in Act II’s Presentation of the Rose and the closing of Act III. Stephen Costello filled the hall with Italianate squillo and thrilling top notes as he navigated with aplomb the many landmines in the treacherous pastiche Strauss wrote for The Italian Singer. Had the score invited applause, he would have stopped the show. Instead, he had to wait three hours for final bows to receive the audience’s roar of approval. Jane Henschel and Graham Clark had some sly fun with the scheming Italians, Annina and Valzacchi and their tossed salad of German/Italian gibberish. Though he battled to be heard at times, Alan Opie was an appropriately proud then exasperated Faninal. Irmgard Vilsmaier’s Marianne epitomized the strength of the rest of the cast. A soprano with Isolde and Brünnhilde in her repertoire, she was imposing and authoritative and left one eager to hear her in more substantial roles.

Strauss admonished sopranos not to treat the end of the first act as the Marschallin’s “tragic farewell to life”. Rather, he urged them to play the moment “with Viennese grace and lightness, one eye wet and the other dry,” a description which aptly describes Nelsons’ way with the score. No sentimentality or sugar-coating dulls the sharp edges and bittersweet undercurrents of Hoffmanstahl’s libretto and the waltzes often lurch into Mahler territory. However, Nelsons still needs to master Symphony Hall’s acoustics when it comes to opera. Freed from the pit, Strauss’ large orchestra can easily overpower singers in a hall which favors it. Some of the audibility problems the singers faced were from a lack of calibration in this respect. Otherwise, this is an interpretation which can only benefit from the complete staging Nelsons will conduct in December.

The Marschallin thinks stopping the clocks in her house will stop time, but soon realizes it continues to flow nonetheless, like sand in an hourglass. Those spilling sands have whispered to Renée Fleming that the time has come to bid farewell to staged opera. She will do so as the Marschallin in a new production shared by Covent Garden and the Metropolitan Opera. With one eye wet, the other dry, we wish her well.