Complex sentence: He attended the Italia Conti Stage School where his teacher suggested he audition for a boyband that was being put together by Simon Cowell and he was chosen along with four other boys to be part of internationally successful boyband Five.
Split into simpler sentences: He attended the Italia Conti Stage School where his teacher suggested he audition for a boyband that was being put together by Simon Cowell. He was chosen along with four other boys to be part of internationally successful boyband Five.