In the late 1960s and the early 1970s, some rock music enthusiasts pushed the limits of blues-rock into a new genre they called the Heavy Metal Rock. Many bands in the genre emerged and with a brisk pace rock music developed as a craze in the United Kingdom and in the United States. With its roots in blues rock and psychedelic rock, bands that played heavy metal were characterized by highly amplified distortion they created in their music. With deep rooted lyrics and immensely loud music – metal bands have ever since filled stadiums and facilities with cheers and banging heads. Here are top10 metal bands ever!