Who Was Leonard Bernstein? All About the Maestro Subject's Wife, Family and Career

The life of late composer Leonard Bernstein is immortalized in the 2023 film Maestro, starring Bradley Cooper as Bernstein himself.

Best known for creating the music for West Side Story, Bernstein enjoyed a prolific career as a composer and conductor before he died in 1990. However, it is his marriage to Felicia Montealegre (played by Carey Mulligan) — and his infidelities — that are the focus of the new biopic. Bernstein and Montealegre were married from 1951 to 1978 and had three children together: Jamie, Alexander and Nina.

While Bernstein's daughter Jamie praised his parenting during her youth in her 2018 memoir, Famous Father Girl: A Memoir of Growing Up Bernstein, Bernstein wasn't faithful to his wife and, much to Montealegre's emotional distress, he had relationships with men before and during their marriage.

All three of the late composer's children played a big role in helping director, writer, and star Cooper develop Maestro, which is now streaming on Netflix. As Jamie told PEOPLE, instead of building a movie that began with Bernstein’s birth and ended with his death, Cooper “decided to tell this incredibly personal, up-close, intimate story of our family.”

That story wasn’t always an easy one to tell, however. In between the magnificent highs the composer enjoyed are stories of an emotional toll that Jamie believed contributed to their mother’s early death in 1978.

Still, Cooper said that the family relationship was the most compelling part of Bernstein’s life. The actor explained, “After doing a year of research on Lenny and the family and letting everything soak in, I realized the most interesting and relatable aspect to me was this marriage between Lenny and Felicia. It was an unorthodox, genuine love that I found endlessly intriguing.”

So who was Leonard Bernstein? Here's everything to know about the Maestro subject's life, family and career.

He grew up in Massachusetts

Though his parents immigrated to the United States from Ukraine, Bernstein was born in Lawrence, Massachusetts.

According to the Leonard Bernstein Office, Bernstein began playing piano as a child. NPR reported that his father, Sam, believed that Bernstein would eventually join the family business in the hair and beauty products industry and even refused to pay for the lessons.

Despite that setback, Bernstein made it to Harvard University, where he studied with Walter Piston, Edward Burlingame-Hill and A. Tillman Merritt. He also spent his summers at the Boston Symphony’s seasonal home, Tanglewood, where he connected with conductor Serge Koussevitzky and composer Aaron Copeland, who both took the young man under their respective wings.

He made his debut as a conductor on Nov. 14, 1943

Bernstein was pulled in two directions as an adult and had a hard time deciding if he wanted to be a composer or a conductor. In the end, he did both. He made his debut as a conductor on Nov. 14, 1943, after the original conductor for a concert at Carnegie Hall fell ill.

He later recalled to his brother Burton in 1989 that he didn’t feel totally prepared for the moment, saying, “There were times when I must have fantasized — you know, one of those days — 'Someday, son, this will all be yours,' as they say. But I never thought I would have to walk out there [the Carnegie Hall stage] on my own. When it came to the time — that very day — all I can remember is standing there in the wings shaking and being so scared.”

Bernstein was entirely successful in the performance. As he said, “I strode out and I don't remember a thing from that moment — I don't even remember intermission — until the sound of people standing and cheering and clapping.”

He married Felicia Montealegre in 1951

Bernstein first met his future wife, Montealegre, at a party in 1946 — the same year she made her Broadway debut in Swan Song. Per the Leonard Bernstein Office, the two became engaged quickly though called it off.

They later reconnected in 1951 and wed the same year.

He was a father of three

The maestro and Montealegre had three children together: daughters Jamie and Nina and son Alexander. In her memoir, Jamie wrote of her father, “In my mind’s eye, my father is always in a scruffy brown wool bathrobe; my cheek still prickles at the memory of his scratchy morning hugs.”

“My father was just all about the heart. He conducted from the heart. He taught from the heart,” Jamie told PEOPLE in 2023. “He would've hugged every person in the world if he could have. But he managed to do that pretty well with his own music and his music making. That was his way of hugging everybody.”

Still, Bernstein had a "competitive" nature, as his eldest child explained to the Los Angeles Review of Books in 2018. “We were all certainly encouraged to be successful in the world. But it wasn’t overt," she shared. "There was this implicit understanding that there could only be one superstar in the family. Everyone else was at a lower level."

He had intimate relationships with male colleagues before and during his marriage

Despite his love for Montealegre, Bernstein wasn't always faithful. He had relationships with music producer and clarinet player David Oppenheim, and later, with his research assistant Tommy Cothran.

As Jamie told PEOPLE in 2023, “He was bisexual and had this whole other life having relationships with men."

However, Bernstein's children seemingly did not know of their father's liaisons growing up. While speaking to CBS Sunday Morning in November 2023, Nina said, “Our mom was the most elegant, delicious person,” with Jamie adding of Montealegre, “She knew exactly what the deal was.”

Still, Jamie also believes that her mother’s early death from lung cancer in 1978 at the age of 56 might have been due in part to the emotional toll that Bernstein’s relationships took on her. She said, “I feel like it cost her everything to stick with it. It was really tough for her, and I think it contributed to her early death in a way.” But her brother Alexander added, “I wouldn’t go that far. I think, you know, probably she regretted a lot of things looking back.”

His Young People’s Concerts introduced families to classical music

Bernstein also brought classical music into the lives and homes of families throughout the United States. His Young People’s Concerts were considered one of his “greatest achievements," per the Leonard Bernstein Office.

He conducted the first concert in the series in 1958. He later said that the shows were “among my favorite, most highly prized activities of my life.” Bernstein led over 50 concerts throughout the following 14 years, each recorded and televised on Saturday mornings.

His Jewish heritage inspired his work

Bernstein was born into a Jewish family, and his Jewish heritage was inspirational to him throughout his life. His first large-scale work, “Symphony No. 1: ‘Jeremiah’ (1943),” was inspired directly by his culture and faith, per the Leonard Bernstein Office.

The conductor also said that his first memory of music was at Mishkan Tefila, a synagogue in Massachusetts. He later said in an interview, “I felt something stir within me, as though I were becoming subconsciously aware of music as my raison d’être.”

He also composed “Symphony No. 3: Kaddish” and “Chichester Psalms” in Hebrew-Aramaic.

He composed West Side Story

In 1957, Bernstein composed the music for what would become one of the most celebrated musicals of all time, West Side Story. After the show’s opening night, Bernstein wrote that it took a lot to bring it from composition to the stage. As he put it, “All the peering and agony and postponement and re-re-rewriting turn out to have been worth it.”

Bernstein also scored movies, including 1954's On the Waterfront, for which he was nominated for an Academy Award.

He died on Oct. 14, 1990

The 1980s were not an easy decade for Bernstein. His daughter Jamie wrote in her memoir of the time, “Everything had become such an effort for him: his breathing, his insomnia, and all the additional threescore-and-ten indignities. His belly was terribly distended; while the rest of him seemed to be collapsing in on itself.”

On Oct. 14, 1990, Bernstein died of a heart attack brought on by ''progressive emphysema complicated by a pleural tumor and a series of pulmonary infections,'' his physician told The New York Times. He was 72.

He is played by Bradley Cooper in the 2023 biopic Maestro

The biopic Maestro hit theaters for a limited release run on Nov. 22, 2023, and is currently streaming on Netflix. The film received largely positive reviews after it first premiered at the Venice Film Festival in September, with critics praising Cooper and Mulligan's performances.

Bernstein's son Alexander added of Cooper's portrayal, per Netflix, “Bradley’s brought pretty much all of my dad’s facets as a creator. You get rehearsal scenes, you get teaching scenes, you get a composing scene, obviously conducting scenes and how about that piano playing! Just tremendous."

Matt Bomer, Sarah Silverman, Maya Hawke, Miriam Shor and Gideon Glick also star in the film.