Renée Fleming has had a busy week here in Boston. Besides rehearsing and appearing with the Boston Symphony, on Monday she gave a talk at MIT talk on music and neurobiology. “There’s so much to learn about how and why music engages the brain, and even alters the brain,” said Fleming, the world-renowned soprano who in recent years has been working with the medical community to develop new research programs linking music and neuroscience. Tuesday afternoon she coached four voice students from B.U. ant N.E.C. The first floor of Jordan Hall was full, mostly, it appeared, from a show of hands, with voice students. Who could blame them for being Renée wannabes? This celebrated soprano was at the top of her operatic game for over 25 years, and she still looks, dresses, and sings better than 99% of the population. From this and another master class at Harvard I attended a few years ago, one gathers she really is interested in helping other singers, and is, to boot, both rather funny and very nice.

I am still not sure how one gets up the nerve for singing for perhaps the most celebrated soprano of our time, but these young women had nerves of steel. Singer #1 (Elaine Dauber) sang Gounod’s “Jewel Song.” Renée’s observations: “In almost every role we do, we (sopranos) get only five minutes to be happy. If there’s not a terrible outcome or cathartic experience, the audience is disappointed….Figure out who you’re looking at and singing to…. Your knees are locked. We mustn’t be distracted by wondering if you’re comfortable. (The singer tosses off her heels, and is now barefoot). “We need to see a gesture to show us she’s trying on the jewels.” When she sees the jewels, “This is not an opportunity for a high note; it’s to show surprise!… In each phrase we need to know you’re in the moment!”

Singer #2, (Rebecca Printz) sang Strauss’s Wie du warst. “We need more detail. When people do this well, we don’t realize they’re singing. See yourself as a conduit,” Renée gets Rebecca to sing with a pencil in her mouth. “Sing E up and over the pencil.” Finally, “Don’t sing like my generation. I’d like to sound younger like you.”

Singer #3 Saori Erikson, sang Charpentier’s Depuis le jour. “This is the float aria of all time,” at which Fleming proceeded to talk about what to do with one’s body to sing well, “I need expansion under my armpits. When I take in breath, my whole back, torso, ribcage expand. Keep that expansion through the length of the phrase…. Alexander Technique is so great. Take at least one class!”  Get out of your own way! I sing so well when I’m (not thinking and) blow-drying my hair!”

Thursday evening at the BSO, dedicated to the memory of André Previn, opened with Richard Strauss’s opulent Sextet from Capriccio, played gorgeously by violinists Tamara Smirnova and Haldan Martinson, violists Steven Ansell and Cathy Basrak, and cellists Blaise Déjardin and Adam Esbensen. Andris Nelsons conducted. What was extra special about this performance (besides the beautiful playing) was that beforehand all the players had left the stage, so the 7 musicians walked onto an empty stage, and when it was over, left, and then joined the rest of the orchestra filing in quietly. This occurs in other orchestras, and I think it would be lovely to do it more often. It imparts a sense of occasion.

The All-Strauss program continued with “Moonlight” music and the last scene from Capriccio. Strauss operas have always been Fleming’s calling card, and they always perfectly suited her voice, as she has remarked many times. One might recall how Fleming, in 2009, opened the Metropolitan Opera season with three scenes- one was Capriccio. Her previous BSO appearance, two years ago, featured her as the Marschellin in Der Rosenkavalier, and her voice was still lustrous. Whoever heard Fleming in the Met’s Eugene Onegin, or with her friend mezzo-soprano Susan Graham in their duo concert here several years ago (2013), or at Tanglewood in Strauss’s Four Last Songs in 2016, might have extremely fond memories of her mellifluous voice, which has, unsurprisingly as she faces 60, changed. In her last Scene of Capriccio here, unlike in an opera house, she was standing on the same level as the large orchestra, so she was somewhat drowned out. Her voice seemed quieter than I remembered, and it made one wonder about her idea there years ago not to do opera anymore. Her voice now is more ideally suited to the lighter singing in musicals, in which she seems to be immensely popular worldwide.

Interestingly, the highlight of the whole program was Fleming’s encore, “I Can Smell the Sea Air” by her friend André Previn, “the artist who gave us incomparable beauty.” It came from his 1999 opera A Streetcar named Desire, in which she was his chosen Blanche du Bois. Her voice in this sweet offering was in its best form of the night, and her performance was a balm to the many people in the audience who mourned the loss, last month, of this remarkable musician.

Nelsons has been building a reputation with Thus Spake Zarathustra. Those of us at a certain age know the opening from Stanley Kubrick’s 1968 film “2001: A Space Odyssey,” although I imagine most have never gotten past the infamous first few measures. How amazing then to hear them live in Symphony Hall. No recording can compare with this, from the foundation notes in the organ up to the stratosphere of Nietzschesque über-decibels. If much felt unnecessarily rushed, the quieter, more contemplative parts fared better than their rambunctious counterparts.

Throughout the evening I must acknowledge the seriously impressive playing of hornist Richard Sebring in Capriccio, harpist Jessica Zhou, First Associate Concertmaster Tamara Smirnova, and trumpet Thomas Rolfs whose solos in Also sprach were simply stunning.

Susan Miron is a book critic, essayist, and harpist. She writes about classical music and books for The Arts Fuse. Her last two CDs featured her transcriptions of keyboard music of Domenico Scarlatti.