Bass is the lowest voice-part.
It goes (from lowest to highest): bass, baritone, tenor, contra-alto, alto, mezzo-soprano, soprano
Bass.
The lowest singing voice is the male voice called bass.
a bass is the lowest male singing voice.
Bass is the name of a very low male singing voice.
The lowest normally recognised is the 'contralto'.
The lowest female voice is called contralto.
Bass
pitch
Bass.
Contalto
The lowest female voice is the Contralto; also considered the rarest in occurrance.
Bass Baritone
Baritone