Thomas was born on December 21, 1944, in Los Angeles, California, Thomas, a
Broadway stage manager and a middle school history teacher, respectively. He was the grandson of
Yiddish theater stars
Boris and
Bessie Thomashefsky, who performed in the
Yiddish Theater District in Manhattan. The family talent goes back to Thomas's great-grandfather, Pincus, an actor and playwright, and before that to a long line of
cantors; his father, Theodor Herzl Tomashefsky (Ted Thomas), was also a poet and painter. Thomas studied piano with John Crown and composition and conducting with
Ingolf Dahl at the
University of Southern California, where he graduated from the USC Thornton School of Music '67 and MM '76. As a student of
Friedelind Wagner, Thomas was a Musical Assistant and Assistant Conductor at the
Bayreuth Festival. As a young man, he was driving and heard music "so powerful I pulled over to the side of the road." It was
James Brown singing "Cold Sweat". He credited Brown with influencing his musical timing.
Boston, Buffalo, New York, and Los Angeles From 1968 to 1994, Thomas was the music director of the
Ojai Music Festival seven times. After winning the
Koussevitzky Prize at
Tanglewood in 1969, he was named assistant conductor of the
Boston Symphony Orchestra. That same year, he made his conducting debut with the orchestra, replacing an unwell
William Steinberg mid-concert and thereby coming into international recognition at the age of 24. He stayed with the Boston Symphony as principal guest conductor until 1974 and made several recordings with the orchestra for
Deutsche Grammophon. He was music director of the
Buffalo Philharmonic Orchestra from 1971 to 1979, and recorded for
Columbia Records with the orchestra. Between 1971 and 1977, Thomas also conducted the series of
Young People's Concerts with the
New York Philharmonic as well as the Young Musicians Foundation Debut Orchestra based in Los Angeles. From 1981 to 1985, he was principal guest conductor of the
Los Angeles Philharmonic Orchestra. During a 1985 performance of Mahler's
Eighth Symphony at the
Hollywood Bowl, a (police) helicopter flew over the venue, disrupting the concert. Thomas temporarily left the stage. In 2007, he returned to the Hollywood Bowl, leading the Los Angeles Philharmonic again in the Mahler Eighth, asking jokingly, "Now where were we?"
New World Symphony In 1987, Thomas founded the
New World Symphony in
Miami Beach, Florida, an orchestral academy for young musicians whose stated mission is "to prepare highly-gifted graduates of distinguished music programs for leadership roles in orchestras and ensembles around the world". He played an instrumental role in the development of the
Frank Gehry-designed
New World Center in Miami Beach, which opened in 2011, and maintained a relationship with the organization as Artistic Director Laureate. (The two had personal history: Gehry sometimes baby-sat for Thomas when both were growing up in Los Angeles.
San Francisco Thomas became the
San Francisco Symphony's 11th music director in 1995. He made his debut with the orchestra in January 1974 conducting Mahler's
Symphony No. 9. During his first season with the San Francisco Symphony, Thomas included a work by an American composer on nearly every one of his programs, including the first performances ever by the orchestra of music by
Lou Harrison, and culminated with "An American Festival", a two-week focus on American music. During his tenure, the orchestra began to issue recordings on its own SFS Media label. He conducted Elvis Costello's
Il Sogno. at Carnegie Hall, 2019 In April 2005, he conducted the
Carnegie Hall premiere of
The Thomashefskys: Music and Memories of a Life in the Yiddish Theater, partly as a tribute to his own grandparents. Other American orchestras have since performed this production, including the Chicago Symphony Orchestra, Los Angeles Philharmonic, Boston Symphony Orchestra,
Philadelphia Orchestra, New York Philharmonic, New World Symphony, and San Francisco Symphony. It has also been recorded for future broadcast on
PBS. Thomas collaborated with
YouTube in 2009 to help create the
YouTube Symphony Orchestra, an orchestra whose members were selected from 30 countries based on more than 3,000 video auditions on YouTube. The orchestra, with soloists such as
Mason Bates,
Measha Brueggergosman,
Joshua Roman,
Gil Shaham,
Yuja Wang, and Jess Larsen, participated in a classical music summit in New York City at the
Juilliard School over three days. The event culminated in a live concert at
Carnegie Hall on April 15. The concert was later made available on YouTube. On March 20, 2011, Thomas also conducted the "YTSO2" (YouTube Symphony Orchestra 2) in Sydney. In October 2017, the orchestra announced that Thomas would conclude his tenure as its music director at the close of the 2019–2020 season, and subsequently take the title of music director laureate. Thomas was featured on the 2020 album
S&M2 with thrash metal band
Metallica and the San Francisco Symphony. Thomas only conducted during the performance of "Scythian Suite, Opus 20 II: The Enemy God and the Dance of the Dark Spirits", "The Iron Foundry, Opus 19", and "The Unforgiven III", and then conducted "Enter Sandman" before moving to keyboards and leaving
Edwin Outwater conducting the symphony orchestra.
As educator Thomas was also devoted to music education. He led a series of education programs titled
Keeping Score which offers insight into the lives and works of great composers, and led a series of Young People's Concerts with the New York Philharmonic. He founded the New World Symphony in Miami in 1987. Thomas led two incarnations of the YouTube Symphony Orchestra, which brings young musicians from around the world together for a week of music making and learning. Thomas served as president of the Tomashefsky Project, a $2 million undertaking formed in 2017 that is intended to record and preserve his grandparents' theatrical achievements, and was on the faculty of the
University of Southern California Thornton School of Music. Due to health concerns, Thomas announced on March 2, 2022, that he would be stepping down as the artistic director of the New World Symphony and instead serve as the artistic director laureate.
Personal life Thomas lived in San Francisco. He married Joshua Robison on November 2, 2014. The two were together for 50 years, having first met as 11 and 12 year-olds in a junior high orchestra. Robison died on February 22, 2026, at the age of 79. On August 6, 2021, Thomas disclosed publicly for the first time that he had been diagnosed with an aggressive form of brain cancer, called
glioblastoma multiforme. On January 9, 2022, Thomas returned to his hometown to conduct—for the first time since his cancer disclosure—the Los Angeles Philharmonic. Despite the small audience at
Walt Disney Concert Hall due to more than 43,000 newly-diagnosed cases of
COVID-19 in Los Angeles County, Thomas was greeted warmly. He proceeded to lead a concert of works by
Gabriel Fauré, Thomas's own
Meditations on Rilke—wistful reflections on life and death as the composer turned 75 in 2019—and to conclude, a performance of Prokofiev's
Fifth Symphony. In 2023, Thomas was featured in the
American Masters documentary
Michael Tilson Thomas: Where Now Is. In February 2025, Thomas announced that his brain tumor had returned. His final public appearance was on April 26, 2025, when he conducted the San Francisco Symphony in a belated 80th birthday celebration concert. On April 22, 2026, Thomas died of the disease at his home in San Francisco, at the age of 81. == Film and television ==