Plot: Broadcast of Prom 57: Swing No End Singer and broadcaster Clare Teal heads the charge in this big band spectacular. Travel back in time with this rip-roaring Prom to the 1930s and 1940s and celebrate the irrepressible music of Duke Ellington, Benny Goodman, Count Basie, Tommy Dorsey, Stan Kenton and more, plus a special tribute to the unassuming giant of the big band world, Mary Lou Williams