Born in Argentina in the early '40s, the peripatetic Gregorio also lived in Los Angeles (where he studied with saxophonist Warne Marsh) and Vienna, before eventually settling in Chicago. After moving to Vienna from California in the late '80s, Gregorio met and began collaborating with the free jazz flügelhornist Franz Koglmann. The Swiss hatART label discovered Gregorio through his association with Koglmann. The company released his first album, Approximately, in 1996; two subsequent efforts -- Ellipsis and Background Music -- were later released on the label's hatOLOGY offshoot.

Growing up in Buenos Aires, Gregorio's first jazz influences were early jazz clarinetists Pee Wee Russell and Jimmy Noone. He eventually became interested in the music of pianist Lennie Tristano and his circle; their cool aesthetic would have a decisive impact on his mature concept (Ornette Coleman's innovations also had their effect). Gregorio studied modern classical music, as well as art and architecture. He's worked in the latter two fields and teaches Art Appreciation at Purdue University. In the '60s, Gregorio played experimental music in and around Buenos Aires; some of his work from that time is documented on the Atavistic release Otra Musica: Tape Music, Fluxus Free Improvisation in Buenos Aires 1963-70. ~ Chris Kelsey, Rovi