Karen Borca is the only Bassoonist who has made a mark in Avant-Garde Jazz and Free Jazz.  Her bands have played The Berlin Jazz Festival, Taklos Festival in Switzerland, Jazz Happening in Finland, The Vision Festivals  in USA and many other concerts, clubs and venues.  Her Quartet and 10 peice ensemble "Tentet" played in the Newport Jazz Salute to Women in Jazz Festivals in '78 & '79.  She was a representative of the US as a member of Canaille, an international group of women composers,  which played at the Gulhbenkian Art Center in Lisbon, Potugal in 1990.

She has played and recorded with some of the most important pioneers of Avant-Garde Jazz and Free Jazz including Cecil Taylor, both as a member of his large ensembles and Unit from '70-'89, Jimmy Lyons, for 12 years , Bill Dixon, Andrew Cyrille, William Parker and more.