Assertion: contralto's voice | /r/HasProperty | rare
Facets:
Source sentences:
text: Also known as alto, the contralto is the lowest female voice and a true operatic contralto is rare, so much so that roles intended for this voice type often go to mezzo-sopranos.
text: A "true" contralto voice is considered rare, and as such, many contralto roles are frequently sung by mezzo-sopranos.