Mark Snow, the composer best known for creating the haunting and iconic theme song for The X-Files, has passed away at the age of 78. Snow died at his home in Connecticut on Friday, July 4, 2025. While a cause of death was not immediately provided, news of his passing has prompted an outpouring of tributes from fellow composers, colleagues, and fans alike.

Born Martin Fulterman in Brooklyn, New York, on August 26, 1946, Snow's musical journey began with piano lessons at age 10. He later mastered the drums and oboe, developing a passion for baroque and renaissance music. Snow attended the High School of Music & Art and then the prestigious Juilliard School, where he met and formed a lasting friendship with fellow composer Michael Kamen. Together, they formed a band called Emil and the Detectives, which later evolved into the New York Rock & Roll Ensemble. The band, active from 1968 to 1970, released three studio albums that fused classical music with rock music.

Snow's interest in film music was ignited by Jerry Goldsmith's score for Planet of the Apes. In 1974, he moved to Los Angeles with his wife, Glynn, to pursue his passion for composing for the screen. His first job came six months later, composing for an episode of Aaron Spelling's The Rookies. He composed music for television in the late 1970s. His early work included TV shows like Starsky and Hutch, Hart to Hart, and T.J. Hooker.

While Snow had a successful career before The X-Files, it was his work on the science fiction series that catapulted him to international fame. He was recommended to the show's creator, Chris Carter, by R.W. Goodwin, a co-executive producer and mutual friend. Snow composed music for over 200 episodes of the show and two X-Files feature films. The eerie, whistling tune he created for the series became a cultural phenomenon, reaching No. 2 on the UK Singles Chart in 1996 and being named one of the "100 Greatest TV Theme Songs of All Time" by Rolling Stone in 2022.

Snow recounted that the iconic X-Files theme came about by accident. While experimenting on a keyboard, he hit a key with his elbow, producing a sound that became the foundation of the series' distinctive music. Snow worked on the show for its initial nine-season run from 1993 to 2001 and returned for the revival seasons from 2015 to 2018.

Beyond The X-Files, Snow's prolific career included composing music for numerous other television series, such as Millennium, Smallville, Ghost Whisperer, One Tree Hill, and Blue Bloods. He also composed for video games, including Syphon Filter: Dark Mirror and Urban Assault.

Snow was nominated for 15 Emmy Awards throughout his career, six of them for The X-Files. He also received nominations for his work on Ghost Whisperer and the television miniseries An American Story and Children of the Dust. In 2016, he received an ASCAP Award for Most Performed Themes and Underscore.

Fellow composer Sean Callery remembered Snow as a generous mentor, saying, "He would give the most inspiring and intelligent feedback".

Mark Snow is survived by his wife, Glynnis, their three daughters, Sarah, Megan, and Nora, and several grandchildren. His legacy as a composer who shaped the sound of television will undoubtedly endure for years to come.