Complex sentence: His manager helped him record a demo that eventually made its way to Carly Simon, who heard the demo and then invited James to come and record a song with her that would play at the 2003 Nobel Peace Prize ceremony.
Split into simpler sentences: His manager helped him record a demo that eventually made its way to Carly Simon, who heard the demo and then invited James to come and record a song with her. That song would play at the 2003 Nobel Peace Prize ceremony.