Twenty-five year old Leonard Bernstein, Assistant Conductor of the New York Philharmonic-Symphony Orchestra, is shown at the piano at Carnegie Hall in New York City, Nov. 14, 1943. (AP Photo) (ASSOCIATED PRESS/ASSOCIATED PRESS)

Leonard Bernstein is the musician we love to love and love to patronize. Even 24 years after his death, we treat him much as we did when he was alive. Oh, Lenny, we say with affectionate eye-rolling, there he goes again: a piece of pop-music sweetness in a supposedly “serious” work, an attempt at philosophizing that sounds so simplistic as to be toe-curling (in, for example, “Dinner with Lenny,” a long interview from 1989 with Jonathan Cott that Oxford University Press brought out as a book in 2013).

And then, in spite of yourself, you get pulled in. You’re still listening to the music, and it’s taking you somewhere you didn’t expect, and it’s kind of great. You keep reading the book and you end up wishing you were a guest at that dinner. And in the end you love him all the more. How great he could have been, we might think, had he not been, well, so much himself.

His friends were saying it from the start of his career. “Your driving ambition to be the most versatile creature on earth will kill any possibility of your becoming a truly great artist in any one of the talents you possess,” wrote Shirley Gabis (later Perle), a sometime girlfriend. This letter was written in early 1944; Bernstein was 25. (“The Leonard Bernstein Letters,” which includes this missive, are coming out in paperback this fall.)

Yet it turns out Lenny was truly great after all: one of the biggest, most colorful, most popular and recognizable figures in American classical music. And posterity shows no signs of abandoning him. Recording catalogues and publishers’ lists are as full as ever of his recordings, DVDs and Bernstein-related publications (this week, Yale University Press is bringing out a new biography by Allen Shawn, in the series “Jewish Lives”).

And as the music world gears up for the Bernstein centenary in 2018, the music lives on — to a far greater extent than many people would have imagined in 1975 or 1985, when Bernstein was seen as composing ambitious failures.

“I’m pleasantly impressed,” says Marin Alsop, music director of the Baltimore Symphony Orchestra and a Bernstein protégé, in a recent telephone interview, “by the value that his music seems to hold, and the esteem [with which] he’s regarded as a composer, because that was such a struggle, wasn’t it, during his lifetime. . . . People couldn’t listen to his music objectively. That’s been so gratifying to me, to see how well his music does live on, and how it’s appreciated by the next generation.”

Objectively or not, they are indeed listening — and performing it. An all-Bernstein concert by the Master Chorale of Washington on Oct. 5 will feature a cross-section of his choral music, from early work to the “Missa Brevis” of 1989, his last choral piece, to the perennially popular “Chichester Psalms.” “That is one piece,” says Alsop, “that seems to have been elevated to the rarefied air of ‘West Side Story.’ ” She will lead it herself on a BSO program in November that also includes Bernstein’s first symphony, “Jeremiah,” which will be recorded as the final link in a cycle of all three Bernstein symphonies with the BSO on Naxos. In June, the BSO will present a concert performance of another enduring Bernstein work, “Candide.”

Speaking of “West Side Story,” there’s a new recording of that, too, from Michael Tilson Thomas, another of Bernstein’s most successful protégés, music director of the San Francisco Symphony and the New World Symphony. In evaluating Bernstein’s compositional legacy, Tilson Thomas gravitates more toward the stage work. “It remains to be seen how history will evaluate those things,” he said via phone last week from San Francisco, of Bernstein’s later and more aspirationally “serious” work. “But it’s unquestionable that some of these perfect songs and little pieces strike us as iconic, stake out a territory that we recognize as important to our inner lives. Some of these slow major-minor things in dance sequences in “On the Town” or “Fancy Free;” a song like “Some Other Time” or “There’s a Place for Us.” It’s music that haunts all of us. Talk about building large structures — it’s woven into the structure of your entire life.”

It’s a big claim on one hand and on the other, a left-handed compliment. Bernstein so desperately wanted to be taken seriously by the musical world as a composer of symphonies, not of songs. Yet he was a born populist, and populizer, in the best sense: the sense of wanting to share music he loved and making it accessible to a wider public — as a composer and as a conductor.

“He created the mold,” says Tilson Thomas, “the model for the socially responsible, inclusive, generous maestro, as opposed to the remote, preoccupied, professorial — although God knows he could be professorial. He wasn’t the kind of high-priest conductor, or professor conductor, or inspector-general conductor, or reign of terror conductor. He was like, ‘Hey, we’re all in this together; let’s explore together.’ It’s something people still get, and aspire to.”

Certainly Tilson Thomas and Alsop have followed in his footsteps as they spearhead the current push of orchestras to expand beyond their traditional concert halls to find new ways of interacting with the community through educational programs (including BSO’s OrchKids), social media and broadcast initiatives such as Tilson Thomas’s ambitious radio and television series “Keeping Score.”

Is it too early to speak of legacy? The music world is still heavily populated with people who worked directly with Bernstein. Tilson Thomas cites the “West Side Story” dance suite, a frequent item on concert programs. “It’s notated a certain way,” he says, “but we all play it the way it’s supposed to go. . . . It’s the flavor of how much it’s swung, how much in front of the beat or in back of the beat it’s supposed to be: That’s a different thing depending on whether it’s swing, mambo, or all the other dance music in that piece.” Classically trained musicians aren’t always the best exponents of Bernstein’s music: Tilson Thomas chose to use singing actors, rather than classically trained singers, for his “West Side Story” recording. One wonders whether future recordings will increasingly tend to sound like Kristjan Jarvi’s account of the sprawling, genre-bending “Mass” with an Austrian orchestra — slightly too obedient and scrubbed and careful.

But perhaps the very process of performing Bernstein’s music forces people to find their own answers — in a very Bernsteinian spirit. “He was somebody who loved to ask questions,” Tilson Thomas says, “and follow those questions with still more questions.”

For her part, Alsop remembers the stories he would tell about pieces, some of them completely fabricated and unrelated to any intention of the composer’s. “The first story he ever told me was the story of Roy Harris’s Third Symphony,” she says. “There is no story. But he made up a fantastic one” involving a grandfather sitting in a rocking chair with his grandson, in front of a fire — this about a movement the composer referred to as “tragic.” Trite? Maybe. But who cared. “I fell in love with the piece,” Alsop says.

It’s clear that Lenny remains all things to all people. A couple of generations of music lovers — musicians and listeners alike — can recount their own Bernstein experiences and name their favorite Bernstein moments, and the disparity of the responses demonstrates something important about the artist. Bernstein’s genius was the genius of music: to forge a personal connection, ignite a spark that no one else can share, because it is so vital to the individual listener who treasures it. The question, or the story, of Lenny’s legacy turns out not to be how he is remembered by posterity. It’s how he is remembered by you.

The Washington Master Chorale’s Choral Tribute to Leonard Bernstein takes place at 4 p.m. Oct. 5 at the National Presbyterian Church. www.washingtonmasterchorale.org.

The Baltimore Symphony Orchestra’s Bernstein & Beethoven program takes place Nov. 21-23 at the Joseph Meyerhoff Symphony Hall and the Music Center at Strathmore; “Candide” follows in June, 2015. www.bsomusic.org.