Mark Snow was born in Brooklyn, the son of a professional percussionist and a kindergarten teacher who had a definite love for blues piano. As a youth, Snow learned piano and drums, then fell in love with the oboe. An aficionado of Baroque and Renaissance music, Snow entered the New York Music and Art School, where he befriended composer Michael Kamen, another oboe fan, with whom he would be roommates for several years at Juilliard. Studying as broad a variety of music as possible, Snow gradually became fascinated with contemporary popular music, going on to form the New York Rock 'N Roll Ensemble with Kamen in 1968, the band signing almost immediately to Atco. The band was notable for a mix of rock and classical elements, gathering attention for their live shows. After five albums for Atco and Columbia, the band broke up.
Snow then took the advice of his wife, Glynn, the sister of actors Tyne Daly and Tim Daly, and moved to California. He very quickly found work in television, scoring shows and pilots for Aaron Spelling, beginning with The Rookies, for which he scored individual episodes. A prolific composer, Snow was much in demand for both television series work and for TV movies, with an impressive list of credits that included everything from Hart to Hart to The Oldest Living Confederate Widow Tells All.
In 1993, Snow was tapped by producer Chris Carter to provide music for The X-Files, a risky horror/science fiction series debuting on the young Fox network. After several attempts at a piece of title music yielded only frustration, Snow played a few arpeggios through an echo device, drawing a positive response from Carter. An eerie melody line was quickly generated, but it then took Snow some time to figure out the right voice to use. In an inspired move, Snow had his wife, Glynn, whistle the melody, which he then sampled and doubled with the "Whistling Joe" patch from an Ensoniq Proteus synthesizer module. The resulting piece of music, received with great uncertainty at Fox, quickly became one of the key selling points of the new show. Several versions of the music would be generated for album release, including a popular extended version found on Songs in the Key of X. Warner Bros. eventually released The Truth and the Light, mixing Snow's music with dialogue from the series.
As prolific as ever, Snow went on to score Carter's Millennium series while maintaining the pace on The X-Files. In addition, he also provided themes and scores for other series, TV movies, and low-budget features. While not seen as a major film and television composer, Snow certainly made his mark with The X-Files, and in 1999 released The Snow Files: Film Music.