Complex sentence: Leven was born in Chicago and is of Irish descent and his most famous song is arguably "Cruella de Vil" from the 1961 Disney animated feature "One Hundred and One Dalmatians".
Split into simpler sentences: Leven was born in Chicago and is of Irish descent. His most famous song is arguably "Cruella de Vil" from the 1961 Disney animated feature "One Hundred and One Dalmatians".