Simplify the following text for a Grade 7 native English-speaking person.
Original: Many non-disco artists recorded disco songs at the height of disco 's popularity , and films such as Saturday Night Fever and Thank God It 's Friday contributed to disco 's rise in mainstream popularity .
Simplified: Disco was at its most popular in the United States and Europe in the 1970s and early 1980s . Disco was brought into the mainstream by the hit movie Saturday Night Fever , which was released in 1977 .