Complex sentence: The Velvet Underground was an American rock band, active between 1964 and 1973, formed in New York City by Lou Reed and John Cale, who both went on to find success as solo artists.
Split into simpler sentences: The Velvet Underground was an American rock band formed in New York City. First active from 1964 to 1973, its best-known members were Lou Reed and John Cale, who both went on to find success as solo artists.