n. (pl. -os)
1. CONTRALTO.
2 a the highest adult male singing-voice, above tenor. b a singer with this voice. c a part written for it.
3 a (attrib.) denoting the member of a family of instruments pitched second- or third-highest. b an alto instrument, esp. an alto saxophone.
Phrases and idioms:
alto clef a clef placing middle C on the middle line of the staff, used chiefly for viola music.
Etymology: It. alto (canto) high (singing)