Complex sentence: Billy Thorpe and the Aztecs were an Australian pop and rock group dating from the mid-sixties which re-emerged in the early Seventies to become one of the most popular Australian hard-rock bands of the period.
Split into simpler sentences: Billy Thorpe and the Aztecs were an Australian pop and rock group dating from the mid-sixties. They re-emerged in the early Seventies to become one of the most popular Australian hard-rock bands of the period.