Mezzo-soprano
Middle female voice.
What it means
The mezzo-soprano is the middle female voice range between soprano and alto. The range usually reaches roughly from low G to A″ and overlaps largely with that of the soprano; decisive, therefore, is not the reach but the colour: a fuller, darker core in the middle register and a sustaining depth. Within the category, lighter, coloratura-capable and heavier, dramatic types are distinguished, as well as transitional forms toward the alto.
Musical use
In opera the mezzo-soprano takes on a great range of roles: youthful male figures in trouser roles, confidantes and antagonists of the soprano parts, plus numerous leading roles of their own weight. In oratorio and concert repertoire it is represented with arias in the middle register; in the Lied it covers a large part of the repertoire, which is often published in several keys. In choir the range is usually distributed between second sopranos and first altos; it does not form a choral part of its own.
Performance practice
Seek the core of the voice in the middle register and do not let yourself be guided in fach assignment by individual top notes. Work deliberately on the register transitions, which can become especially audible in the mezzo-soprano, and practise them in calm legato lines without increasing volume. Keep the low register free of pressure: a forced chest voice costs the high register in the long run. Choose repertoire that fits your own colour, instead of taking over parts after role models. Watch for even vocal warm-up and for recovery periods, especially in demanding roles.
Bear in mind that the boundary to the soprano and to the alto is fluid and many singers change their assignment over the course of their careers: get advice and decide by colour and stamina, not by individual top notes. Check, with a given part, how much time it spends in which register. Choose repertoire that matches the vocal colour, for mezzo-soprano parts range from lyric to dramatic. Watch for even vocal warm-up.
Check, with trouser roles, whether costume and movement impair breath support, and rehearse such passages scenically.