In the late ‘20s, jazz musicians like Earl “Fatha” Hines and Fletcher Henderson formed orchestras built for dancing. The swing rhythm replaced the old two-beat meter, and by the mid-’30s the new sound pushed the burgeoning appeal of jazz into the mainstream, turning Benny Goodman and Ella Fitzgerald into pop stars. Riffs were layered upon riffs, with concise, ebullient solos folded into the brisk performances. Bandleaders like Glenn Miller and Tommy Dorsey developed a sleeker sound, reducing the improvisation and emphasising Tin Pan Alley melodic sophistication. While the swing era ended after World War II, the format has never vanished.