Complex sentence: His career started with being the lead vocalist for I Killed the Prom Queen; he is currently the lead vocalist of Confession, and is also a former vocalist for Carpathian and Bury Your Dead.
Split into simpler sentences: His career started with being the lead vocalist for I Killed the Prom Queen. He is currently the lead vocalist of Confession, and is also a former vocalist for Carpathian and Bury Your Dead.