alto

In choral music, the alto (from the Latin altus, high) is the lowest female voice or the highest male voice, typically ranging from F3 to F5. The term originally referred to a high male voice in medieval music — the countertenor. In modern practice, altos are usually female singers, while the male equivalent is called countertenor. As an instrument designation, alto describes the mid-range member of an instrument family: alto saxophone, alto flute, alto clarinet. The viola is sometimes called the alto in French and German. The alto clef (C clef on the third line) is used primarily by the viola.