John Zinga, a descendent of slaves, has an ancient medallion around his neck and a fragment of song passed down generations. He is an English dockworker with a magnificent voice and a yearning to learn his roots.

Paul Robeson
as John 'Johnny' Zinga

Elisabeth Welch
as Ruth Zinga

Esme Percy
as Gabriel Donozetti

Robert Adams
as Monty

James Solomon
as Native Leader

Tony Wane
as Mandingo (as Ecce Homo Toto)

Ronald Simpson
as Mr. Blane, the Pianist

George Mozart
as Bert Puddick

Jenny Dean
as Marian

Joan Fred Emney
as Nell Puddick