He demonstrates the enormous diversity and constant change that characterized every aspect of music during this period.  By dividing his text into twenty-year spans, Downs is able to trace the development of musical style.  Within each span he looks at the social conditions and daily life of the musician, and the aesthetics and audience preferences in structures, performing combinations and styles.  The lesser composers, or Kleinmeister, are observed, since they are the most accurate mirrors of their times.  Haydn, Mozart and Beethoven receive full biographical scrutiny at each stage of their development.  Copious music examples and abundant illustrations are also provided.