Bach, bahk, Johann Sebastian (1685-1750), a German composer, is considered the greatest genius of Baroque music. A highly complex and dramatic style, Baroque music reached its peak in the early 1700's. Like most art of the Baroque period, Baroque music emphasized continual motion. In his compositions, Bach brought such musical techniques as counterpoint and fugue to their greatest heights. Counterpoint is the playing of two or more melodies at one time. Fugue is a composition in which different instruments repeat the same melody with slight variations. See Baroque; Counterpoint; Fugue.