This month, the National Symphony Orchestra is celebrating the 150th anniversary of Richard Strauss’s birth with two programs almost entirely devoted not to symphonic music, but opera. The first was a one-off performance of the composer’s most beloved opera, “Der Rosenkavalier,” starring Renée Fleming, at the Kennedy Center Concert Hall on Saturday night.

We love to love “Der Rosenkavalier.” It’s an opera about nostalgia: a 20th-century meditation on loving and growing old and letting go, packaged in a glittering 18th-century wrapping shining with satin and powdered wigs and the glint of chandeliers. And it’s redolent of many of the things we love about opera: its outsized beauty and glamour and a whiff of anachronism and swaths of luxuriously beautiful music. It appeals to our best selves — our eager youth, our generous middle age — and balances on the line between profundity and the near-maudlin that Strauss walked so masterfully in so many of his works.

On Saturday, it brought out the best selves of many of the performers, starting with Fleming, who as the Marschallin (a married woman in her 30s having an affair with a 17-year-old boy) sang with honesty, clarity, a beautiful silvery tone and an innate dignity. She put the focus on the words and the character rather than on how she was bringing them across.

Add to this two dynamite last-minute substitutions and you had a pretty delightful night at the opera. Stephanie Houtzeel, in a stunning, warm, empathetic, coltish, vivid and, one hopes, career-boosting performance, plays the title character, Octavian. Mario Chang, is assured (if a little tight in the tiptop notes) in the fiendishly difficult, blink-and-you’ll-miss-it part of the Italian Tenor, who serenades the Marschallin in her morning room.

There are drawbacks to the concert format, particularly in an opera with an orchestra this big. At first, it was hard to hear everybody over the dozens of instruments on stage, usually safely distanced in the orchestra pit. The proceedings got off to a slightly shaky start with an overture that sounded like a lot of people playing at the same time but not necessarily together.

Stephanie Houtzeel plays Octavian in the National Symphony Orchestra's production of "Der Rosenkavalier." (Julia Wesely)

But the ear adjusted, and the players made it work, as Christoph Eschenbach interacted with the singers and did his best to respond to them. Stephen Pickover created a semi-staging in which “semi” seemed to mean that some of the characters were in costume and some weren’t but that offered enough visible activity to create the impression of an actual production. And having the text center stage, in supertitles over the orchestra’s head, gave everyone the time and space to focus on the librettist Hugo von Hofmannsthal’s words, in the mouth of the Marschallin, about how it feels to realize that you are getting older.

The sense of opulence was certainly reflected in the casting, which drew on an international pool of talent. Fleming is one of today’s leading Strauss singers. Franz Hawlata, the blustering bass well cast as the Marschallin’s blustering cousin Baron Ochs, has been singing around the world for years. Even the smaller parts were cast with strong voices: Irmgard Vilsmaier as the duenna Marianne, Catherine Martin as Annina, Adrian Eröd as Faninal, and Soloman Howard in two small roles as the notary and the policeman. It will be sad for Washington when Howard moves on from the Domingo-Cafritz program at the Washington National Opera and is no longer available to bring such a strong profile and voice to minor roles. I never paid particular attention to the policeman before, but I did on Saturday night.

But, of course, the opera rises and falls with its three female leads: the Marschallin, Octavian and the young Sophie, whom Ochs plans to marry but who falls in love with Octavian instead. And all three women, on Saturday, were admirable, including the Sophie of Marisol Montalvo, who acted convincingly as a slightly petulant, slightly spoiled 15-year-old and sang with such crystalline, delicate high notes in the key scene when Octavian presents her with a silver rose as a token of her engagement to Ochs that I was prepared to forgive her anything.

The figurative rose of the night went to Houtzeel, who last sang in the Concert Hall in Opera Lafayette’s “Armide” in 2010 and who has since sung Octavian and other roles at the Vienna State Opera. She was completely convincing in the part, carrying off the wooing of two other women in concert dress without the slightest vestige of awkwardness and more than holding her own with Fleming with her easy-sounding vocal warmth. But Fleming deserved a rose of her own for her lovely, moving performance. And like all good “Rosenkavaliers,” this was one that audiences here could start to wax nostalgic about almost as soon as it was over.