Ability to sing; utter (5)
I believe the answer is:
voice
I believe this is a double definition.
'ability to sing' is the first definition.
(I've seen this before)
'utter' is the second definition.
(I know that voice is a type of utter)
(Other definitions for voice that I've seen before include "Spokesperson" , "Opinion; part in a fugue" , "Opinion; express in words" , "Ability to speak, sing" , "Utter - part" .)