In the '60s and '70s, much (if not most) contemporary improvisation was jazz-based. That began to change in the '80s, when a significant number of rock musicians began exploring the possibilities of free improvisation and new classical forms. Fred Frith is one of the more prominent. Co-founder of the underground British band Henry Cow in 1968, composer/improviser/guitarist Frith moved to the U.S. in the late '70s, where he began associations with such New York-based experimental musicians as cellist Tom Cora, harpist Zeena Parkins, saxophonist John Zorn, and percussionist Ikue Mori. Frith lived in New York for 14 years; some of his well-known ventures in that time included Massacre (with Bill Laswell and Fred Maher), Skeleton Crew (with Cora and Parkins), and his sextet Keep the Dog. In the '80s, Frith's compositional activities increased; he began writing for dance, film, and theater, and for such ensembles as the Rova Saxophone Quartet, Ensemble Modern, Asko Ensemble, and his own Guitar Quartet. Primarily known as an improvising guitarist, Frith has also performed on bass (with Zorn's Naked City) and violin (with Lars Hollmer's Looping Home Orchestra). Frith has played on albums by the Residents, Brian Eno, Amy Denio, and René Lussier, to name just a few. Frith was the subject of Step Across the Border, a documentary film by Nicolas Humbert and Werner Penzels. By 2000, Frith was a professor of composition at Mills College in Oakland, CA, and continued to release a bevy of albums including Eleventh Hour in 2005. In 2007, Frith began the year by releasing Impur and The Happy End Problem on ReR, and followed them with Sugar Factory and a live album (recorded at the N.Y.C. venue The Stone) on the Tzadik label, and finished it with Cutter Heads with Chris Brown on Intakt. Frith was less prolific in 2008 but nonetheless released the fine To Sail, to Sail on Tzadik. He picked up the pace in 2009, as Still Urban and The Big Picture saw issue on Intakt. He continued with three releases in 2010, including Dictée/Liber Novus and Eye to Ear, Vol. 3, which appeared on Tzadik, and Live in Japan for ReR.