Nick Barraclough pays tribute to arguably one of the least recognised jobs in pop, that of the backing vocalist. Tracing the evolution of vocal harmony from Medieval canon through to Gladys Knight and the Pips, he draws a straight line from the ‘Fa-la-las’ of Tudor song through to 50s doowop with the help of arranger and musicologist Harvey Brough. Along the way we'll hear examples of the art from The Shangri-Las to Steely Dan, and find out what happens when session singers mover their larynxes.