In response to Mr Di Saia's letter, an exact definition of heavy metal music, or any musical genre for that matter, is difficult because a musical style encompasses a number of features, including the beat, lyrics, and performance styles. The National Academy of Recording Arts and Science, which awards a Grammy in the category of heavy metal music, has no formal definition of this genre. Heavy metal music most often has been characterized as hard driving, dominated by the electric guitar, and heavily amplified. After controlling for modern technology, heavy metal music conceivably could parallel the music of Paganini in an earlier era.Roe1 discusses the correlation between poor school performance and preference for rock and punk music. The author studied social background, gender, orientation to parents and peers, interest in popular music and preference for musical genres, television use, future educational plans, and occupational expectations.