Complex sentence: After leaving the Orange County-based band Sylvia (later emerging as ANYONE), he joined up as the drummer for Sass Jordan, which in turn he left to act as the drummer for Alanis Morissette.
Split into simpler sentences: After leaving the Orange County-based band Sylvia (later emerging as ANYONE), he joined up as the drummer for Sass Jordan. He left to act as the drummer for Alanis Morissette.