If the 1930s was the Swing Era, then the years from 1937 on might well be called the Jump Era. That summer Count Basie recorded "Jumping at the Woodside," and suddenly jump tunes seemed to be everywhere. Along with the bouncy beat came a new dance step -- the high-flying aerials of the jitterbuggers -- and the basketball games that took place in the dance halls of African America became faster, higher, and flashier. Duke Ellington and a cast of hundreds put the buoyant spirit of the era on stage with their 1941 musical revue, Jump for Joy, a title that captured the momentum and direction...