Boy, pop singer needs one! (4)
I believe the answer is:
mike
I believe this clue is a double definition.
'boy' is the first definition.
'pop singer needs one' is the second definition.
(microphone)
(Other definitions for mike that I've seen before include "Man" , "Comms code for M" , "-- Oldfield, musician" , "that helps speaker to be heard" , "T [Thespian] Reid" .)