Lacy began his career at sixteen playing Dixieland music with much older musicians such as Henry "Red" Allen, Pee Wee Russell, George "Pops" Foster and Zutty Singleton and then with Kansas City jazz players like Buck Clayton, Dicky Wells, and Jimmy Rushing.^[1] He then became involved with the avant-garde, performing on Jazz Advance (1956), the debut album of Cecil Taylor,^[2]: 55 and appearing with Taylor's groundbreaking quartet at the 1957 Newport Jazz Festival; he also made a notable appearance on an early Gil Evans album.^[1] His most enduring relationship, however, was with the music of Thelonious Monk: he recorded the first album to feature only Monk compositions (Reflections, Prestige, 1958) and briefly played in Monk's band in 1960^[3]: 241 and later on Monk's Big Band and Quartet in Concert album (Columbia, 1963).

Lacy's first visit to Europe came in 1965, with a visit to Copenhagen in the company of Kenny Drew; he went to Italy and formed a quartet with Italian trumpeter Enrico Rava^[1] and the South African musicians Johnny Dyani and Louis Moholo (their visit to Buenos Aires is documented on The Forest and the Zoo, ESP, 1967). After a brief return to New York, he returned to Italy, then in 1970 moved to Paris, where he lived until the last two years of his life. He became a widely respected figure on the European jazz scene, though he remained less well known in the U.S.

The core of Lacy's activities from the 1970s to the 1990s was his sextet: his wife, singer/violinist Irene Aebi,^[2]: 272 soprano/alto saxophonist Steve Potts,^[4] pianist Bobby Few, bassist Jean-Jacques Avenel, and drummer Oliver Johnson (later John Betsch).^[1] Sometimes this group was scaled up to a large ensemble (e.g. Vespers, Soul Note, 1993, which added Ricky Ford on tenor sax and Tom Varner on French horn), sometimes pared down to a quartet, trio, or even a two-saxophone duo. He played duos with pianist Eric Watson. Lacy also, beginning in the 1970s, became a specialist in solo saxophone; he ranks with Sonny Rollins, Anthony Braxton, Evan Parker, and Lol Coxhill in the development of this demanding form of improvisation.

Lacy was interested in all the arts: the visual arts and poetry in particular became important sources for him.^[1] Collaborating with painters and dancers in multimedia projects, he made musical settings of his favourite writers: Robert Creeley, Samuel Beckett, Tom Raworth, Taslima Nasrin, Herman Melville, Brion Gysin and other Beat writers, including settings for the Tao Te Ching and haiku poetry. As Creeley noted in the Poetry Project Newsletter, "There’s no way simply to make clear how particular Steve Lacy was to poets or how much he can now teach them by fact of his own practice and example. No one was ever more generous or perceptive."

In 1992, he was the recipient of a MacArthur Fellowship (nicknamed the "genius grant").^[4][5]

He also collaborated with a wide range of musicians, from traditional jazz to the avant-garde to contemporary classical music. Outside of his regular sextet, his most regular collaborator was pianist Mal Waldron,^{[3]: 244–245} with whom he recorded a number of duet albums^[4] (notably Sempre Amore, a collection of Ellington/Strayhorn material, Soul Note, 1987).

Lacy played his 'farewell concerts to Europe' in Belgium, in duo and solo, for a small but motivated public. This happened in Brussels, Antwerp, Ghent, Bruges and Mons. In duo he played with Fred Van Hove, Joëlle Léandre, Mikhail Bezverkhni, Irene Aibe, Frederic Rzewski, Christopher Culpo and the dancer Shiro Daimon. This recollection is published by Naked Music, Afkikker, Ghent. In Ghent he played with the classical violinist Mikhail Bezverkhni, winner of Queen Elisabeth Concours. Two of these concerts were organized by Rita De Vuyst, his last muse in Europe, to whom he dedicated his solo CD Mother Goose solo @ afkikker. This CD is published within the book, Bone, a tribute to Lacy. He returned to the United States in 2002, where he began teaching at the New England Conservatory of Music in Boston, Massachusetts. One of his last public performances was in front of 25,000 people at the close of a peace rally on Boston Common in March 2003, shortly before the US-led invasion of Iraq.

After Lacy was diagnosed with liver cancer in August 2003, he continued playing and teaching until weeks before his death on June 4, 2004 at the age of 69.^[1]

As leader/co-leaderEdit

CompilationsEdit

• Blossoms, farewell concerts to Europe, Naked Music, Afkikker

With Mal WaldronEdit

As sidemanEdit

• Discography