Experimental rock
There was always experimentation in rock music, but it was not until the late 1960s that new openings were created from the aesthetic intersecting with the social. In 1966, the boundaries between pop music and the avant-garde began to blur, and rock albums began to be conceived and executed as distinct, extended statements. Rock musicians (mostly unschooled) in the middle and late 1960s drew from the work of composers like John Cage, Karlheinz Stockhausen, and Luciano Berio. Academic Bill Martin acknowledges: "in the case of imitative painters, what came out was almost always merely derivative, whereas in the case of rock music, the result could be quite original, because assimilation, synthesis, and imitation are integral parts of the language of rock."