The terms "heavy metal" and "hard rock" have often been used interchangeably, particularly in discussing bands of the 1970s, a period when the terms were largely synonymous.<ref>Du Noyer (2003), pp. 96, 78</ref> For example, according to an entry in the 1983 ''[[Rolling Stone]]'' encyclopedia, "known for its aggressive blues-based hard-rock style, [[Aerosmith]] was the top American heavy-metal band of the mid-Seventies."<ref>Pareles and Romanowski (1983), p. 4</ref> Few would now characterize Aerosmith's classic sound, with its clear links to traditional [[rock and roll]], as "heavy metal." Even some acts closely identified with the emergence of the genre, such as Led Zeppelin and Deep Purple, are not considered heavy metal bands by some in the present-day metal community.
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Musik