"I consider him a genius," remarked Arnold Schoenberg of the progressive early modernist Max Reger (1873-1916). In addition to his international renown as a teacher, conductor, and pianist, Reger wrote more than 1,000 works in virtually every musical genre. Many scholars and musicians credit him with emancipating dissonance to a level that assisted Schoenberg's development of serialism in the 1920s. Reger's influence extends to other 20th-century...