Leonard Bernstein during a rehearsal in 1977 for a concert with the Israel Philharmonic Orchestra at West Berlin’s Philharmonic Hall. (Galliner/ AP)
Classical music critic

Composer, conductor, activist, teacher, rule-breaker, American icon: Leonard Bernstein was a towering figure for the many American musicians who came in his turbulent wake. And yet, he was not an intimidating one.

“He built you up,” says John DeMain, who led the world premiere of “A Quiet Place,” Bernstein’s last opera, in 1983 at the Houston Grand Opera, where DeMain was for many years music director and principal conductor. “He made all of us exceed ourselves. He made me comfortable.”

Bernstein offered the classical music world a different model. An all-American artist, drawing on American vernaculars in his infectiously popular music, he was neither the impenetrable composer nor the forbidding conductor of which classical music stereotypes are made. His music leapt over genre divisions and, ultimately, helped stake out new terrain in the concert hall for Broadway and the American songbook.

But what may have endured most is the personality: the generous ebullience, the childlike delight in music and in himself that he evidenced when, DeMain remembers, he was writing the four interludes for “A Quiet Place,” bit by bit, and demanded that everyone come to his hotel, the Four Seasons, every day to hear the latest 16 bars of the score. Or when, after the first rehearsal, filled with glee at the sound of his own piece, he got DeMain in a headlock.

Bernstein would have been 100 years old next year, and this season marks the start of centennial observations all around the music world — including a Kennedy Center celebration, from the National Symphony Orchestra’s season-opening Bernstein program Sept. 24 to the Washington National Opera’s final opera of the season, “Candide.”

To many music lovers, Bernstein i s American music — whether they think of him as a conductor championing the symphonies of Gustav Mahler and reaching a wider audience through his televised Young People's Concerts, or as the composer of "West Side Story," a high-water mark in the history of American musicals.

But Bernstein also spotlights some of the fault lines running through the American musical establishment, and the centennial makes it clear that, in spite of his example, they haven’t changed all that much. Ironically, the classical music world will be feting Bernstein in part for his role in merging the American vernacular with high-art music, in works such as “Candide” and “West Side Story.” But throughout his life, critics castigated him for not being serious enough. And even today, the classical music world tends to look down on Broadway, or film scores, as not being fully serious, or somehow tainted. Some of the artists who most energetically took up Bernstein’s mantle as a champion of both musicals and operas — such as DeMain and John Mauceri, who worked closely with Bernstein for 18 years — haven’t always gotten the respect accorded to conductors who focused on the standard European canon.

“The lightest music you perform determines the highest seriousness you’re allowed to pursue,” says Mauceri, a theory akin to the one-drop rule: If you play something “light” (and in the classical music world, a suite from ‘West Side Story’ might still count as “light”), you aren’t expected to be able to play the heavy-hitters in the canon. Indeed, DeMain remembers the Wiener Symphoniker not wanting to play under him while he was leading a revival of “West Side Story,” on the grounds that the musical made him a “jazz conductor.” And one myth, Mauceri says, “is that if you conduct lighter music, you’ve done it for the money.” In fact, he points out, “it’s the music directors who only conduct Mahler who are the millionaires. It’s not the director of the pops program.”

Bernstein himself was never able to resolve this divide. His entire career was shaped by his need to prove himself to the mainstream classical music world. Even “West Side Story” was originally, like an opera, almost entirely sung. In 1982, when DeMain was conducting the 25th-anniversary production of the musical, “he told me he and Sondheim had set words to the entire prologue dance at the gym,” DeMain says. “It was Robbins who said, ‘Lenny, nobody’s going to listen to all of that. We’ll dance that, sing that, talk that.’”

The attempt to please the classical music world only intensified as he got older. Bernstein’s wife, Felicia, was “horrified,” Mauceri says, when Bernstein was asked to record some significant core repertory with the Vienna Philharmonic. But for Bernstein, it was a chance to prove himself yet again. This emphasis on so-called serious music arguably blighted his composing career. Conventional wisdom has it that his concert pieces, including three symphonies, lack some of the spontaneity and brilliance of his stage work, as it strains too hard to make a point.

“There’s no question that the ‘Jeremiah’ symphony is a wonderful work, the violin concerto is wonderful,” Mauceri says. “We know he could write as complex as anybody, in a dazzling way — he could do anything. [But] when is it the Lenny who we want to hear, and when is it the Lenny who wanted to prove something?”

“He always bristled when people wanted to talk about ‘West Side Story,’ ” conductor Leonard Slatkin says. “But when you write a work that virtually reshapes an entire genre, and is beloved by the world, you cannot escape.”

Slatkin has certainly championed Bernstein’s serious concert pieces, and in November, he’ll return to the National Symphony Orchestra, where he was music director for 12 years, to lead “Songfest,” which the NSO commissioned for the Bicentennial. “Songfest” aims to reflect the American spirit by setting the words of 13 poets from different epochs of American history. Even in these works, Bernstein couldn’t, Slatkin thinks, escape his fundamental attachment to narrative.

“For me,” Slatkin wrote in an email exchange, “the five works add up to a summation of Bernstein’s life. ‘Jeremiah’ is the nod to his Jewish heritage and . . . finds the composer still looking for his voice, the one that will please his parents. ‘Age of Anxiety’ [the second symphony] is all about alienation, with Bernstein trying to come to grips with why he is different from pretty much everyone else around him.

“I used to try and find a more symphonic and structural coherence” when conducting these pieces, Slatkin says. “Now, I think they must reflect Bernstein the man, with as much stylistic contrast as possible.”

Given his huge effect on the field, it’s notable that Bernstein, as a composer, has no clear musical heir. Some composers cross between musicals and opera, at least, but few have his gleeful, in-your-face mastery of so many styles and forms. Complicating the issue is that Bernstein’s relationship to the American vernacular tradition was somewhat compromised by the rise of rock, which was much less his world. Young composers today who dabble in popular forms tend to draw from that musical world. If Bernstein has a successor, it’s his onetime collaborator Stephen Sondheim, who has stayed as resolutely away from the institutions and forms of classical music as Bernstein was inexorably drawn to them.

“We begged him to write operas,” DeMain says. “He wouldn’t do it. He said, ‘You guys do a dress rehearsal and you open. I can’t work like that.’” He needed the long development period of a musical’s previews, or out-of-town tryout.

But when we think of Bernstein’s legacy, we tend to think of the many conductors he championed — conductors who, for the most part, work primarily in the concert hall. And the distinctive features of Bernstein’s legacy on the podium are not as much an embrace of musicals as they are physical features — an active, athletic approach, talking to the audience and introducing pieces before playing them. The musicians who came after Bernstein watched him make his own, tortured, sui generis way in the compositions he wrote. But they experienced firsthand the warmth, generosity and encouragement of a man who, rather than sitting in stony judgment on a young conductor leading his music, embraced him in a headlock.

“Some people can have a profound influence on you when you know them a large part of your life,” Mauceri says. “Others can have an equal influence with a moment, a line, a sentence.” Bernstein had that kind of power. “When you think of the thousands of musicians who experienced Lenny directly,” Mauceri adds, “whether they worked with him for a week, or watched him at Tanglewood, that influence is huge and ongoing.”

The National Symphony Orchestra opens its season with a Bernstein gala Sept. 24 and performs “Songfest” with Leonard Slatkin on Nov. 2 and 4, for the Kennedy Center’s season-long festival “Bernstein at 100.”