Michael Tilson Thomas, a leading American conductor for a half-century who headed orchestras in Buffalo, Miami, London and San Francisco while also composing, died Wednesday. He was 81.

Tilson Thomas had surgery for a brain tumor in 2021 and resumed his career, then said in February 2025 the tumor had returned. He conducted his final concert with the San Francisco Symphony in April 2025 and died at his home in San Francisco, spokesperson Connie Shuman said.

Tilson Thomas received 39 Grammy Award nominations, winning 12, and was among the Kennedy Center Honors recipients in 2019.

"It's meant to have various intriguing and alluring, questioning things that you hear on first hearing," he said of classical music during a 2004 interview with The Associated Press. "But by its very nature it's holding a lot of other secrets or a lot of other perspectives much closer to its chest, which only with repeated hearing you start realizing are there."

Tilson Thomas was born in Los Angeles on Dec. 21, 1944, to a family steeped in the arts. His father, Ted, was a producer at New York's Mercury Theater Company, then worked in Los Angeles in the movie and television industry. His mother, Roberta, headed research for Columbia Pictures. His grandparents, Bessie and Boris Thomashefsky, were pioneers in American Yiddish theater.

He played piano at a young age and attended the University of Southern California. By the time he received a degree in 1967, he had worked with Pierre Boulez, Aaron Copland, Igor Stravinsky and Karlheinz Stockhausen.

"I don't fling the word genius around lightly, but I fling it around about Michael. He reminds me of me at that age, except that he knows more than I did," conductor Leonard Bernstein told The New York Times Magazine for a 1971 profile. "Not only music, but things like the functions of the brain, cerebrology, physics, biochemistry."

Tilson Thomas was the co-music director and then music director of California's Ojai Festival in the late 1960s and early 1970s. He was an assistant at Germany's Bayreuth Festival in 1966, won the Koussevitzky Prize at the Tanglewood Music Center in 1968 and became a Boston Symphony Orchestra assistant conductor in 1969.

Tilson Thomas made his New York debut at Lincoln Center's Philharmonic Hall on Oct. 22, 1969, as a mid-concert replacement for an ailing William Steinberg. Tilson Thomas led Robert Starer's Concerto for Violin, Cello and Orchestra, and Strauss' "Till Eulenspiegel."

"A tall, thin young man, he came on stage with an air of immense confidence and authority, and showed that his confidence was not misplaced," critic Harold C. Schonberg wrote in the Times. "He takes naturally to this music, as might be expected of a Tanglewood graduate and a pupil of Pierre Boulez."

Tilson Thomas became the BSO's principal guest conductor from 1972-1974 and was music director of the Buffalo Philharmonic from 1971-79 and a principal guest conductor of the Los Angeles Philharmonic from 1981-85.

He helped found Miami's New World Symphony in 1987 and served as artistic director until 2021. He was principal conductor of the London Symphony Orchestra from 1988-95 and music director of the San Francisco Symphony from 1995-2020.

Tilson Thomas' compositions include "Grace" (1988), "Four Preludes on Playthings of the Wind" (2015-16) and "Meditations on Rilke" (2019).

His husband, Joshua Robison, died Feb. 22 while recovering from a fall suffered last August. They met while playing in the orchestra of North Hollywood Junior High School (since renamed Walter Reed Middle School), became partners in 1976 and married in 2014.

In announcing his final concert would take place in San Francisco on April 26, 2025, in a belated 80th birthday celebration, Thomas issued a statement acknowledging his mortality.

"At that point we all get to say the old show business expression, 'It's a wrap,'" he said. "A coda is a musical element at the end of a composition that brings the whole piece to a conclusion. A coda can vary greatly in length. My life's coda is generous and rich."