Complex sentence: His first great moment of fame occurred when he joined Chick Corea's Return to Forever in 1973, recording Hymn of the Seventh Galaxy, though he quit in 1974 and was replaced by Al Di Meola.
Split into simpler sentences: His first great moment of fame occurred when he was with Chick Corea's Return to Forever from 1973 to 74, recording Hymn of the Seventh Galaxy. In 1974 he quit Return to forever and was replaced by Al Di Meola.