Mozart's contribution to Opera

Composer Contributions TASK: Talk about Mozart's contributions to opera music. You may provide some information about the Mozart's life and briefly mention other composers that influenced him, but your focus should be on your subject's works and how Mozart differed from or expanded on the works of others before him. Do NOT give a biography of your composer. At least three reputable outside sources are required (different authors/publications/websites). Do not use any dictionary/encyclopedia sources, except oxford/grove music(this may only be used once).