Aloysius Tyrone Foster was born January 18, 1943, in Richmond, Virginia, and moved with his family to Harlem, New York, as a child, growing up on 140th Street. His father, an amateur bassist, put a drum kit in front of him early, and his older brother played congas; Foster later said he was captivated by Max Roach's playing around age twelve and started on drums in earnest at thirteen. Harlem in the 1950s put him within walking distance of the Apollo Theatre, where he saw Miles Davis perform live in 1958 — fourteen years before the two men would work together.

Foster made his first recorded appearance at twenty, on trumpeter Blue Mitchell's 1964 Blue Note album The Thing to Do, and spent the rest of the 1960s as a freelance drummer around New York's hard-bop and swing scenes, recording and touring with Blue Mitchell and Illinois Jacquet among others — steady, unglamorous sideman work that built a reputation among musicians years before it built a public one.

That reputation reached Miles Davis in 1972. Davis heard Foster play live at the Cellar Club on West 95th Street in Manhattan and later wrote in his autobiography, "He knocked me out because he had such a groove and he would just lay it right in there... Al could set a groove and just leave it there, humming, all night." Jack DeJohnette was on his way out of the band, and Davis knew immediately who he wanted in the chair. Foster's name already turns up in the personnel for On the Corner, recorded that June and July alongside DeJohnette and Billy Hart across the album's rotating cast of drummers — evidence he was sitting in with Davis's studio band before formally becoming its regular drummer that fall, starting with the live In Concert recording at Philharmonic Hall that September. Davis's regard for him ran deep enough that he named a piece after him, "Mr. Foster," included on that same album.

For the next three years Foster anchored the most abrasive, funk-and-noise-driven music of Davis's career: the sprawling grooves of Big Fun (1974, compiled from sessions dating back to 1969) and the concert recordings that closed out the era, Agharta and Pangaea, both drawn from the same February 1, 1975 double-header at Osaka's Festival Hall. Foster's drumming holds the floor under electric guitars, wah-wah trumpet, and Pete Cosey's noise textures without ever losing the pocket that first caught Davis's ear. Later that year Davis withdrew from performing and recording almost entirely, beginning a retirement that stretched past five years.

Foster didn't sit still during the layoff. He worked through the second half of the 1970s as one of New York's most trusted acoustic-jazz sidemen, touring and recording with Sonny Rollins — whom he later called one of his musical heroes — as well as Dexter Gordon, McCoy Tyner, and Horace Silver, while beginning a long working relationship with Joe Henderson, whose own career is covered in full in his JazzProfiles.com profile, that would eventually produce some of the most important recordings of both their careers. He also stepped out as a leader for the first time, releasing the Japan-only albums Mixed Roots (1978) and Mr. Foster (1979).

When Davis mounted his comeback at the end of the decade, Foster was the drummer he called back — the only musician to serve in Davis's band both before and after the retirement. Foster drummed on the full run of Davis's 1980s comeback albums for Columbia: The Man with the Horn (1981), We Want Miles (1982, which won Davis the Grammy for Best Jazz Instrumental Performance, Soloist), Star People (1983), Decoy (1984), and You're Under Arrest (1985), Davis's last studio album for the label. Guitarist John Scofield, whose own career is covered in full in his JazzProfiles.com profile, joined the band during the Star People sessions and stayed through You're Under Arrest, overlapping with Foster across three consecutive albums. Foster left the band after You're Under Arrest; Davis signed with Warner Bros. for the rest of his career.

Foster's post-Davis decades were arguably his busiest as a sideman. He drummed on Joe Henderson's The State of the Tenor, Vols. 1 & 2 — the trio recordings, with Ron Carter on bass, taped over three nights at the Village Vanguard in November 1985 that reset Henderson's standing as a major voice — and stayed in Henderson's orbit for An Evening With (1987, a co-billed trio with Henderson and Charlie Haden, whose own career is covered in full in his JazzProfiles.com profile), So Near, So Far (Musings for Miles) (1993, Henderson's own Miles Davis tribute, again with Scofield, alongside Dave Holland), and The Montreal Tapes: Tribute to Joe Henderson (released 2003, but recorded live in 1989, again with Haden). He recorded New York Reunion (1991) with the McCoy Tyner Quartet and Henderson, joined the collective quartet Quest with Dave Liebman, Richie Beirach, and George Mraz, and in 1996 drummed on accordionist Richard Galliano's New York Tango, profiled separately on JazzProfiles.com. He also worked steadily across these decades with Herbie Hancock and guitarist Pat Metheny, whose own career is covered in full in his JazzProfiles.com profile, and in 1999 joined Scofield, saxophonist Joe Lovano, and bassist Dave Holland in the collective quartet ScoLoHoFo, whose sole studio album, Oh!, appeared in 2003.

As a leader, Foster stayed comparatively sparing — by one count, eight albums under his own name across nearly fifty years — but he led working bands steadily from the mid-1990s on, most often billed as the Al Foster Quartet, with pianist Kevin Hays, profiled separately on JazzProfiles.com, a frequent presence. Love, Peace and Jazz!, recorded live at the Village Vanguard in April 2007 with Hays, bassist Doug Weiss, and saxophonist Eli Degibri, drew some of his strongest reviews as a leader. His final chapter came on Smoke Sessions Records: Inspirations & Dedications (2019), Reflections (2022, with Kevin Hays, Chris Potter, and Nicholas Payton), and a posthumous live album, Live at Smoke (2025), drawn from a band including Chris Potter and Brad Mehldau. He also guested on pianist Brad Mehldau and guitarist Peter Bernstein's Better Angels (2024).

Foster performed his final show at Smoke Jazz Club in New York on January 18, 2025 — his 82nd birthday. He died at his home in New York City on May 28, 2025, of a serious illness, according to his longtime partner Bonnie Rose Steinberg. He was 82.

Foster's playing formed around Max Roach's example and stayed groove-first throughout his career: Miles Davis praised the same quality directly, the way Foster "could set a groove and just leave it there," and it's what let him move between radically different musical settings without ever sounding like a visitor. DownBeat's 2025 memorial singled out his distinctive timekeeping approach, describing what it called a "reverse hi-hat" technique as part of what made his playing instantly identifiable. That range — the noise-and-funk electric music of Davis's mid-1970s band, the more song-structured, pop-inflected comeback band of the 1980s, and an enormous acoustic post-bop sideman career in between and after — is what made him one of the most trusted and widely recorded drummers of his generation, called on in turn by Miles Davis, Sonny Rollins, and three decades of Joe Henderson recordings.