Norman Gary Foster was born May 25, 1936, in Leavenworth, Kansas. He started on clarinet at thirteen after his junior high school band director, Olin Parker, played him records by Count Basie and Woody Herman and put together a school jazz ensemble; Foster later said it hooked him on the music for good. He attended Central College in Fayette, Missouri, for two years, then transferred to the University of Kansas, majoring in clarinet and music education and later doing graduate work in musicology and conducting. While still in Kansas in the late 1950s he played in an active local scene alongside trumpeter Carmell Jones and tenor saxophonist Nathan Davis (who later settled in Germany).

Foster moved to Los Angeles in 1961, arriving in a jazz economy that had little patience for a young white altoist working in a cool, lyrical style. In 1962 he met pianist and composer Clare Fischer, who became his teacher and closest early mentor, rebuilding Foster's confidence in his own harmonically intricate, understated approach and giving him steady recording and performing work. Foster became a mainstay of Fischer's reed sections through the 1960s and beyond, and their association produced a run of leader dates on John William Hardy's Los Angeles independent label Revelation Records: Subconsciously (1968), Grand Cru Classé (recorded 1969), and, alongside tenor saxophonist Warne Marsh and Fischer himself, Ne Plus Ultra (recorded 1969) and Report of the 1st Annual Symposium on Relaxed Improvisation (recorded May 9, 1972 at Fischer's Van Nuys studio, released 1973). Marsh, a product of Lennie Tristano's school of linear, harmonically exacting improvisation, became as important an influence on Foster's conception as Fischer was on his harmony; the two men kept recording together into the 1980s.

From its formation in 1973 until 1982, Foster held a chair in the reed section of the Toshiko Akiyoshi-Lew Tabackin Big Band, appearing on alto saxophone and flute across the band's core RCA/RCA Victor catalog: Kogun (1974), Long Yellow Road (1975), Insights (1976), Tales of a Courtesan (Oirantan) (1976), Road Time (1976), Live at Newport '77 (1977), March of the Tadpoles (1977), Salted Gingko Nuts (1979), Sumi-E (1979), Farewell (To Mingus) (1980), Live at Newport II (1980), From Toshiko with Love (1981), and Tanuki's Night Out (1981) - a run that put him in the reed section for every Grammy-nominated album the band cut in the 1970s. The connection outlasted the band itself: Akiyoshi personally produced Warne Marsh Meets Gary Foster (Eastworld/Toshiba-EMI, recorded October 1982 in Hollywood, released 1983), a co-billed studio date with pianist Alan Broadbent, bassist Putter Smith, and drummer Peter Donald, and in 1997 Foster rejoined Akiyoshi's own working quartet, alongside Lew Tabackin and George Mraz, for the reunion album Toshiko Plays Toshiko: Time Stream.

Alongside his jazz work, Foster built one of the longest-running studio careers on the West Coast, active as a woodwind doubler for more than 45 years. He is credited on more than 500 motion picture soundtracks, including Monsters, Inc., Ice Age, and Elf, played several seasons in the house band on The Carol Burnett Show, and appeared in the Academy Awards telecast orchestra roughly thirty times. He performed regularly with the Los Angeles Philharmonic, the Los Angeles Chamber Orchestra, the Los Angeles Opera Orchestra, and the Hollywood Bowl Orchestra, and turns up on studio dates for artists as different as Bob Dylan, Frank Sinatra, Barbra Streisand, Milt Jackson, Prince, and Michael Bublé. He taught for decades alongside all of this, on the faculty of Pasadena City College from 1971 to 1991, as a visiting professor at the University of Missouri, Kansas City from 1984 to 2000, and at UCLA and Cal State Fullerton, and founded Nova Music Studios, his own teaching practice, in Pasadena.

Foster's later recording career stayed close to the same circle of players. Make Your Own Fun (Concord, 1991) reunited him with pianist Jimmy Rowles; Concord Duo Series, Volume 4 (1993), recorded live at the Maybeck Recital Hall, paired him with pianist Alan Broadbent; and Body and Soul (Dedicated to the Memory of Warne Marsh) (1996), cut in Tokyo after Marsh's 1987 death, put him in a two-alto frontline with Lee Konitz, the other major saxophonist to come out of the Tristano school. He kept working into his eighties: Play the Music of Reed Kotler (2001) with trumpeter Bobby Shew, American Jazz Institute Presents Perfect Circularity (2007) with bassist Putter Smith, and Mark Turner Meets Gary Foster (Capri, released 2019 but drawn from a February 8, 2003 concert), a tribute to Konitz, Marsh, and Tristano performed with tenor saxophonist Mark Turner. The California Alliance for Jazz inducted him into its Hall of Fame in 2015. Gary Foster passed away in Los Angeles on May 24, 2026, one day short of his ninetieth birthday.

Foster's playing sits squarely in the cool, linear tradition that runs from Lester Young through Lennie Tristano's school, and jazz critic Zan Stewart placed him alongside Lee Konitz, Paul Desmond, and Art Pepper as one of the style's defining West Coast voices. Two mentors shaped the sound directly: Clare Fischer's harmonically dense, unhurried conception, absorbed in private study starting in 1962, and Warne Marsh's Tristano-derived emphasis on long, evenly weighted melodic lines rather than dramatic contrast. The result was a tone and phrasing built for continuity and warmth rather than attack - a quality that made him equally convincing playing a Fischer big-band chart, a Tristano-school two-horn date with Konitz, or a Hollywood soundtrack cue, and that kept him working across jazz, pop, and classical sessions for more than half a century without the style itself ever hardening into something else.