Along with Led Zeppelin and Black Sabbath, the British band Deep Purple is considered a pioneer of heavy-metal rock music; the group, which has gone through many personnel changes over the years and was once listed by the Guinness Book of World Records as the "world's loudest band," is best known for its two hits, which both peaked at #4 on the Billboard Hot 100: in 1968, "Hush," written by Joe South, and in 1973, "Smoke On The Water," inspired by the burning of the Montreaux Casino in 1971 during a Frank Zappa show which Deep Purple opened.