The Columbia Encyclopedia, Sixth Edition. 2001-07.
contralto
(kntrl´t) (KEY) , female voice of lowest pitch. Originally, the term denoted a second voice set against (contra) a high voice (alto); thus, a second high voice. Since most second parts were for a high male voice or a low womans voice, the term came to mean a low womans voice, pitched about a fifth below the soprano. See also alto; countertenor; voice.