Question: Which American musician, composer, activist and filmmaker whose work is characterized by nonconformity, free-form improvisation, sound experiments and satire of American culture, has collaborated with American keyboard player Tommy Mars?
Sentence (from "Frank Zappa"): In a career spanning more than 30 years, Zappa composed rock, pop, jazz, jazz fusion, orchestral and "musique concrète" works, and produced almost all of the 60-plus albums that he released with his band the Mothers of Invention and as a solo artist.
Relevant evidence: No