Most of the genre's major bands released their most critically acclaimed albums during the years 1971–1976. The genre experienced a high degree of commercial success during the early 1970s. Jethro Tull, ELP, Rush, Yes and Pink Floyd combined for four albums that reached number one in the US charts, and sixteen of their albums reached the top ten. Mike Oldfield's "Tubular Bells" (1973), an excerpt of which was used as the theme for the film "The Exorcist", sold 16 million copies.