Complex sentence: The band was founded in 1972 as a performance art group called The Mystic Knights of the Oingo Boingo, and from 1976 it was led by songwriter/vocalist Danny Elfman, who has since achieved substantial renown as a composer for film and television.
Split into simpler sentences: The band was founded in 1972 as The Mystic Knights of the Oingo Boingo, a performance art group. From 1976 it was led by songwriter/vocalist Danny Elfman, who has since achieved substantial renown as a composer for film and television.