Voice below soprano (4)
I believe the answer is:
alto
'voice below soprano' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for alto that I've seen before include "someone to sing" , "Singing voice between tenor and soprano" , "Kind of singing voice, male or female" , "Unisex vocal range" , "Highest male voice: lowest female voice" .)