Now that Leonard Bernstein's 100th year is about to be celebrated around the world starting on his birthday Aug. 25, the truth can be told: He faced death in Philadelphia — more than once.

First was at the Curtis Institute — one of the more civilized spots in 1940 Philadelphia but not immune to insane jealousies. Inside its Old World environs, a gun-toting student announced his intention to shoot fellow student Bernstein, composer Randall Thompson, and conductor Fritz Reiner. Had the gunman not been hauled away by police, the 20th century could've been without three of its greatest figures.

At the other end of his career, in 1976, Bernstein faced a different kind of death: the pre-Broadway tour of his last musical, 1600 Pennsylvania Avenue. The great composer of West Side Story had returned to his most triumphant medium with Alan Jay Lerner in a bicentennial musical, telling local reporters, "I've never been so confident, so thrilled." Indeed, Bernstein had written some of his best music. But the total package was a disaster and turned out to be his greatest professional failure.

Between those two events, Bernstein's career appeared to be almost nothing but blue skies, starting with his sensational 1943 New York Philharmonic debut, and continuing the following year with his double calling card — Symphony No. 1 ("Jeremiah") and the hit Broadway show On the Town. When he died in 1990 at 72, he was one of the best documented of any musician in modern history, with hundreds of video and audio recordings plus numerous biographies. Is there anything left to discover in this anniversary year?

Much of what unfolds in Philadelphia over the next year, starting with his 99th birthday this month and continuing through his 100th next August, will show the Bernstein we already know: Yes, the Philadelphia Orchestra opens its season with Bernstein's popular film score to On the Waterfront (Oct. 4 at Carnegie Hall). Yes, the orchestra also performs the complete West Side Story (Oct. 12-15 at the Kimmel Center) with its familiar jazz-inflected melodies and stone-in-the-shoe dissonances.  Later (Dec. 7-10), the orchestra joins violinist Hilary Hahn in Bernstein's Serenade — a work marginally known at the time of his death but now solidly in the center of the classical concerto repertoire.

First up on the discovery end of the spectrum is a Sept. 7 Fringe Festival reading for a speculative play titled Love, Lenny by Steven Fisher at the Trinity Center for Urban Life, a few blocks from where Bernstein lived as a Curtis student. The jumping off point is the bisexual Bernstein leaving his wife, Felicia, who declared, "You're going to die a bitter and lonely old man."

Later, the National Museum of American Jewish History, in which Bernstein has a permanent place, opens the door to the inner Bernstein with a special exhibit, Leonard Bernstein: The Power of Music (March 16-Sept. 2, 2018). Among other things, the exhibit includes Bernstein's own annotated copy of Romeo and Juliet, with notes for a show that was first titled East Side Story — evidence of the sometimes-agonizing process of creating music that sounds so effortless.

Some rarely heard Bernstein arrives that same month from Curtis Opera Theatre with the ironically titled 1983 opera A Quiet Place, about the nightmarish underbelly of the American Dream (March 7-11 at the Kimmel Center).

None of this is quite in keeping with the popular image of super-charismatic, always-in-command Bernstein. But smooth lives don't end with an FBI file that's 800 pages long.

Bernstein's early 1950s hiatus from the New York Philharmonic was due to CBS radio, which broadcast all of the orchestra's concerts and unofficially banned him from the airwaves because he lent his name to some left-wing political organizations and was suspected of un-American activities. (He was also a spotty presence at the Philadelphia Orchestra, reportedly because longtime music director Eugene Ormandy harbored professional jealousy.)

Bernstein was so strapped for cash that he returned to Broadway — despite having been ordered not to by his late Boston mentor Serge Koussevitzky — to write the 1953 Wonderful Town. Later on, chronic depression plus a perceived lack of relevance among modernist-music circles of the 1960s and '70s blocked him from what he most longed to do: compose.

On that front, he had nearly as many failures as successes. Though his ballet Fancy Free was a hit, more serious ballets, Facsimile and Dybbuk, are absent among this year's global celebrations. The greatest work of his later maturity — the 1977 Songfest that requires six top-of-the-line opera singers — also goes nearly unnoticed in the coming year.

Despite four Broadway hits, Bernstein had two musicals that fell apart before completion, The Skin of Our Teeth and The Exception and the Rule.

But it is 1600 Pennsylvania Avenue, a chronicle of White House residents, that was the ultimate heartbreaker. Bernstein believed in it to the end of his days, even though well-placed friends like Gore Vidal told him the show was hopeless.

Much of the music survives, including the heartfelt ballad "Take Care of This House," which  opera star Joyce DiDonato will sing on New Year's Eve with the Berlin Philharmonic — and which is likely to resonate among those concerned about the direction of the current White House administration.

What Bernstein most longed to write was a magnum opus opera encompassing the Holocaust. Near the end of his life, he searched in vain for the right librettist. How might his legacy have been different had he lived another five years to write it?

"That's a good question," his daughter Jamie Bernstein said last week. "I don't know if he could've found the right collaboration. And even if he had … he was dependent on uppers and downers to get through his day. It took a toll on his ability to concentrate."

Bernstein was a congenial rebel on virtually every level, rebelling against conservative politics, social injustice, nuclear armament, the hegemony of modernist composition, and musical boundaries of any sort. Most of all, he was in rebellion against himself. During the opera A Quiet Place, he challenged librettist Stephen Wadsworth to forget what he knew about well-made plays.

That inner rebellion also took the form of guilt over the death of his wife, with whom he was reconciled just before the  diagnosis of the cancer that killed her in 1978. He blamed himself for her death, having smoked heavily despite an emphysema diagnosis in his mid-20s. As early as the 1940s, rehearsal tapes indicate a pronounced smoker's cough. Later in life, he would pull out an inhaler in midsentence to

catch his breath. Reportedly, a crumpled pack of cigarettes was found on his deathbed.

"He was a free soul, a free spirit in the sense of the music," Los Angeles Philharmonic music director Gustavo Dudamel said in a video message at a spring news conference at Lincoln Center announcing the centenary festivities.

But Bernstein took a long and winding road to get there. Philadelphia Orchestra violinist Davyd Booth, who worked with Bernstein as a rehearsal pianist, described him during a phone interview as a meticulous presence: "To give yourself great freedom, you had to have the almost straitjacketed discipline in learning the piece." Bernstein would internalize each piece down to the finest detail, in ways that allowed him almost to recompose it in performance.

"I hope I'm going to meet him somewhere in heaven," Philadelphia Orchestra music director Yannick Nézet-Séguin declared at the Lincoln Center conference. Other souls might duck behind an angel to avoid him. Unpredictable in his social graces, Bernstein was known to confront people with devastating accuracy about their shortcomings.

He credited his children with keeping a lid on what he himself called his "maestro-ionics" "At home, he turned into a pumpkin," daughter Jamie recalled. "We're a loud family, and we would just interrupt him."

That may help explain how he maintained the common touch that allowed him to communicate so directly in his televised Young Peoples' Concerts (still available on DVD). Jamie will host an orchestra family concert with some of her father's more child-friendly works Feb. 3.

His message to composers was not "do what I did," but "go where I went" — whether with the jazz piano in his Symphony No. 2 "Age of Anxiety" (to be heard March 16-18 at the Philadelphia Orchestra) or the rock band of Mass — and discover the territory for yourself.

"He got a lot of grief for the style he was writing in — at that time. His music now fits with the current philosophy of being able to write in whatever style suits you," said Philadelphia composer Jennifer Higdon.

One instance of Bernstein's continued appeal was apparent at last month's free Penn's Landing concert by the Philadelphia Orchestra. In the very back, where senior listeners are able to park their walkers and wheelchairs — and struggle to their feet for the national anthem — only a few bars of West Side Story were needed to get them moving, swaying side to side. Clearly, Bernstein continues to defy death.