Return to Forever is a jazz fusion group founded and led by keyboardist Chick Corea. Through its existence, the band has cycled through a number of different members, with the only consistent band mate of Corea's being bassist Stanley Clarke (Stanley Clarke is my favorite Bass man of all time).
Along with Weather Report and Mahavishnu Orchestra, Return to Forever is often cited as one of the core groups of the jazz-fusion movement of the 1970s. Several musicians, including Clarke, Flora Purim, Airto Moreira and Al Di Meola, first came to prominence through their performances on Return to Forever's albums.
After playing on Miles Davis's groundbreaking jazz-fusion albums In a Silent Way and Bitches Brew, Corea formed an avant-garde jazz band called Circle with Dave Holland, Anthony Braxton and Barry Altschul.
However in 1972, after having become a disciple of Scientology, Corea decided that he wanted to better "communicate" with the audience. This essentially translated into his performing a more popularly accessible style of music, since avant-garde jazz enjoyed a relatively small audience.