A bass-baritone is a male singer whose voice is quite low, like a deep baritone, but not quite as low as really deep bass. People started to describe some singers as "bass-baritones" in the 19th century, particularly when the composer Richard Wagner wrote operas which needed singers with that kind of heroic voice. Wagner's roles for bass-baritone include: the Dutchman in Der fliegende Holländer, Wotan/Der Wanderer in the Ring Cycle and Hans Sachs in Die Meistersinger von Nürnberg. Wagner called these roles Hoher Bass ("high bass").
Some bass-baritones often sing baritone roles. Others prefer to sing bass roles.
Famous singers who have been, or are, described as bass-baritone include Hans Hotter, José van Dam, Thomas Quasthoff, Friedrich Schnorr, John Shirley-Quirk, Bryn Terfel and Willard White.