A bass-baritone is a type of singer who are comfortable singing in the middle to low range of pitches that men produce. Normally, the term "bass-baritone" is associated with classical music and opera, but bass-baritone refers to the range and quality of the voice and therefore is applicable to any type of vocal music. Very broadly, the term also can refer to any instrument that plays in the same range as these singers.
Bass-baritones can be seen either as a low baritone or a high bass. They have baritone qualities to their voice, but can reach into deeper, true bass pitches when the musical repertoire requires it. A defining characteristic of this voice type, however, is that the bass-baritone loses some of his power and resonance in the lower part of his range. Even though some of the power in the lower range is sacrificed, the color available with this voice type is highly prized.
The designation of "bass-baritone" did not even truly exist until Richard Wagner specifically called for a high bass in roles for his operas. This means that many scores call for a bass or baritone, not a bass-baritone. It thus is often the discretion of the casting director that decides whether a bass-baritone can sing a role labeled for bass or baritone. The goal of the casting director in these instances is simply to ensure that the vocalist has a range that can handle the pitches present in the role with clarity, power and control.
When bass-baritones sing as members of ensembles, the part they sing is somewhat flexible. For example, in a four-part mixed voice choir with bass, tenor, alto and soprano parts, the bass-baritone sings with the basses, taking the upper pitch or pitches if the bass part divides. In a male trio, the bass-baritone usually sings the middle part. In a male quartet or all-male choir, he sings the third part, above the low basses but below the low tenors. Bass-baritones usually are quite accustomed to this chameleon-like activity, so much so that trained bass-baritones often automatically take the proper pitches in a divided-part score, changing pitches only where the director wants to improve the choir's overall harmonic balance and therefore assigns what to sing.
As with other voice types, bass-baritone singers can be classified broadly as either lyric or dramatic. Lyric means that the singer has a light quality to his voice, although he still can be powerful. Lyrics often possess slightly greater agility of voice due to the fact they tend to have a little less thickness to their vocal cords. Dramatic bass-baritones have a richer, fuller sound.