Free improvisation
Free improvisation or free music is improvised music without any rules, and not in any particular style. Performers may choose to play in a certain style or key, or at a certain tempo, but it is not required.
Free music is a relatively little known genre, and none of its exponents can be said to be "famous" amongst the general public. However, in experimental circles, a number of free musicians are well known, including the guitarist Derek Bailey, and the saxophonists Peter Brötzmann[?] and Evan Parker[?].