Leroy Jenkins, violinist and composer, born March 11 1932; died February 24 2007

Leroy Jenkins, who has died of lung cancer at the age of 74, was one of jazz's boldest explorers of both the violin's and the viola's potential in non-classical music. He belonged to a 1960s generation whose heroes were the free-improvising saxophonists Ornette Coleman (who also taught himself to play the sax-like violin) and John Coltrane.
Unlike such older jazz fiddle virtuosi as the 1920s pioneer Joe Venuti or the swing star Stephane Grappelli, later jazz violinists felt released from classical standards of purity and western lyricism. Coleman's playing drew on country hoedowns and blues as well as jazz, but strayed way outside equal-tempered scales. Jenkins, and his more widely acclaimed student Billy Bang, took a similar course, with the classically trained Jenkins exploring voice-mimicking sounds, 20th-century art music innovations and sometimes the use of an electric wah-wah pedal.
But if Jenkins could subvert his instrument's traditional elegance with a rough, percussive bowing attack and an abrasive tone, his improvisations invariably had the balance and shape of a composer, which he also was. He liked the mantra-like recurring phrase, subtly varied by small alterations and sometimes closed or freshly galvanised by a staccato flourish. His music looked back to the raw, unvarnished jazz violin style of the 1930s pioneer Stuff Smith, but was as modern as Coleman, Coltrane, saxist Anthony Braxton or Bartok.

A radical in music and musical politics, Jenkins was at first drawn to cooperative projects rather than band-leading. He was an early and prominent member of Chicago's influential Association for the Advancement of Creative Musicians (AACM), worked from 1969 to 1970 in the US and Paris with such farsighted improviser/composers as Braxton and trumpeter Leo Smith, and helped sustain the powerful Revolutionary Ensemble improvising trio for six years. From the mid-1970s, he developed his own take on jazz-funk in the avant-fusion band Sting, and then moved toward more contemporary-classical ventures, sometimes with pianist Muhal Richard Abrams.
This development brought Jenkins many commissions and opportunities for jazz-classical collaborations; his work was performed by the Brooklyn Philharmonic and the Kronos Quartet, and his later career saw partnerships with choreographers, writers and video artists.
Born on Chicago's South Side, and encouraged by his pianist mother, Jenkins learned the clarinet, alto saxophone, bassoon, violin and viola as a child, and was playing in St Luke's, the city's biggest Baptist church, by the time he was 10 - sometimes accompanied by pianist Ruth Jones (Dinah Washington). He then joined the Ebenezer Baptist church choir and orchestra, and played alto sax at DuSable high school. He attended Florida Agricultural and Mechanical University on bassoon, but worked as an R&B saxophonist out of college hours, and then became a high-school violin teacher in Mobile, Alabama. Returning to Chicago in the mid-1960s, he became involved with the AACM cooperative, soon establishing himself as free jazz's most inventive violinist. In 1967 he co-founded the Creative Construction Company with Braxton and Smith, which migrated to Paris, where he also recorded with the Coltranesque saxophonist Archie Shepp. On returning to New York, he initially lived in Coleman's SoHo loft.
Jenkins continued to perform with Shepp in the 1970s, and with trumpeter Don Cherry and drummer Paul Motian, but it was the Revolutionary Ensemble that saw some of his most sophisticated work of that decade. As with Chicago's legendary Art Ensemble, the group's materials were African-American music at its widest definition, and its members (Jenkins, bassist Sirone and drummer Jerome Cooper) were multi-instrumentalists who made a bigger and richer sound than the trio line-up suggested.

In the late 1970s, Jenkins worked as a player and composer with pianist Anthony Davis (a classically inclined performer also fascinated by gamelan music) and drummer Andrew Cyrille. The trio often suggested links with the idiosyncratic piano virtuoso Cecil Taylor, but Jenkins also confirmed enduring debts to the influence of saxophone players on such scalding adventures as Brax Stone (dedicated to Braxton) and Albert Ayler: His Life Was Too Short. Jenkins then formed Sting, following Coleman's move to a free-electric music with Prime Time.
Though he mostly suspended recording between the mid-1980s and the early 1990s, he became active on the board of the Composers Forum, the new-music pressure group in New York, worked as a soloist and stepped up his composition output. He also worked in a typically uncompromising quintet led by Taylor, in a duo with Art Ensemble saxophonist Joseph Jarman and, in the late 1990s, in the trio Equal Interest, with Jarman and pianist Myra Melford.
Jazz occupied Jenkins far less in his later career. He composed the opera Mother of Three Sons as a collaboration with dancer Bill T Jones; reworked the Faust legend with hip-hop overtones on 1994's Fresh Faust; and followed it with "a cantata for the departed" called The Negroes Burial Ground in 1996 and the opera The Three Willies.
Yet he remained a dazzling violin improviser. The 1998 album Solo, an unaccompanied set that visited such demanding modal and bebop excursions as Coltrane's Giant Steps and Dizzy Gillespie's Wouldn't You, demonstrated how creatively profound was Jenkins' grasp of orthodox jazz structure, yet how eloquently he could live without it. He is survived by his wife Linda and daughter Chantille.

Leroy JenkinsBold explorer of the violin's free jazz potential John Fordham Friday March 16, 2007 The Guardian