Complex sentence: After leaving the University of Idaho, Bowler moved to Chicago to pursue his dream of becoming a professional singer, and worked with a voice coach in 1935 and 1936, when he moved to New York City and joined the Robert Shaw Chorale.
Split into simpler sentences: After leaving the University of Idaho, Bowler moved to Chicago to pursue his dream of becoming a professional singer, and worked with a voice coach in 1935 and 1936. He then he moved to New York City and joined the Robert Shaw Chorale.