The rule's implementation led to the rise of freeform radio in the late 1960s, where disc jockeys played whatever music they wanted without regard to genre or format, taking advantage of FM's higher sound quality and stereo capability. Most of their playlists tended toward rock of the era; in later years the canon of music and artists that developed evolved into the album-oriented and eventually classic rock formats. This growth often came at the expense of the classical music stations which had previously dominated the FM dial. By the late 1970s FM music stations had more listeners than their AM counterparts, even as they had largely moved away from their freeform roots, and in the 1980s the FCC repealed the rule to help AM stations, which had declined as FM grew.
