Female choir voice (4)
I believe the answer is:
alto
'female choir voice' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for alto that I've seen before include "Singing voice between tenor and soprano" , "Unisex vocal range" , "Singer's hidden inside chemical toilet" , "someone to sing" , "Counter-tenor or contralto" .)