Complex sentence: He began teaching at Berklee College of Music in 1957 and in 1975 suffered a ruptured disc causing Alan to halt touring, leave Berklee and limit his teaching to his home in Lexington, MA.
Split into simpler sentences: He began teaching at Berklee College of Music in 1957. Dawson suffered a ruptured disc in 1975 causing him to halt touring, to leave Berklee and limit his teaching to his home in Lexington, MA.