Complex sentence: She also attended the Interlochen Arts Academy, before going to Yale University (graduated in 1982), where, at the age of eighteen, she sang the role of Mabel in Gilbert and Sullivan's comic opera "The Pirates of Penzance".
Split into simpler sentences: She also attended the Interlochen Arts Academy before going to Yale University, graduating in 1982. At Yale, at the age of eighteen, she sang the role of Mabel in Gilbert and Sullivan's comic opera "The Pirates of Penzance".