Mezzo-soprano, or ‘half-soprano’ is the female voice that stands between the soprano and the contralto.
The mezzo voice is very similar in extension to that of the soprano but has a darker timbre. In fact, mezzos often sing just as high as their soprano counterparts. In addition, operatic mezzos are also divided into the basic coloratura, lyric, and dramatic groups. What sets mezzos apart are their strong middle voices, their smouldering lower registers. If a mezzo and a soprano were to sing the exact same pitch, the mezzo’s note would most likely sound a little bit fuller, darker, or heavier (imagine a clarinet playing the same note as a flute). Mezzos are usually given secondary roles in the opera with a few exceptions (Bizet’s Carmen is a mezzo).