What kind of music is " free music"?
The answer to that is not easy. This is because a fixed music genre called "Free music" does not exist.
However, looking at the music scene in the 20 years between 1960-1980, it would be safe to say that "Free Jazz" and "Collective music in Contemporary music" did fit the bill of "Free music."
Also, we believe that it is the very Free music that looks deeply into society, while also having an influence as the most fundamental element of music, evoking music in all of culture. This is because art and music after Postmodernism also exists...