A bass-baritone is a high-lying bass or low-lying "classical" baritone voice type which shares certain qualities with the true baritone voice. The term arose in the late 19th century to describe the particular type of voice required to sing three Wagnerian roles: the Dutchman in Der fliegende Holländer, Wotan/Der Wanderer in the Ring Cycle and Hans Sachs in Die Meistersinger von Nürnberg. Wagner labelled these roles as Hoher Bass ("high bass")—see fach for more details.
The bass-baritone voice is distinguished by two attributes. First, it must be capable of singing comfortably in a baritonal tessitura. Secondly, however, it needs to have the ripely resonant lower range typically associated with the bass voice. For example, the role of Wotan in Die Walküre covers the range from F2 (F at the bottom of the bass clef) to F♯4 (F♯ above middle C), but only infrequently descends beyond C3 (the C below middle C). Bass-baritones are typically divided into two separate categories: lyric bass-baritone and dramatic bass-baritone.
Bass-baritones should not be confused with their vocal cousin—the so-called Verdi baritone. This type of Italianate baritone voice has a brighter tone colour and sings at a slightly higher tessitura than that possessed by the bass-baritone. In addition to the operas of Giuseppe Verdi, its natural home is to be found in operatic music composed after about 1830 by the likes of Donizetti, Ponchielli, Massenet, Puccini and the verismo composers.