Microphone initially grasped by idle singer? (7)
I believe the answer is:
domingo
'singer?' is the definition.
(I know that Domingo is a tenor)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for domingo that I've seen before include "Placido ......., one of the Three Tenors" , "Santo -, capital of Dominican Republic" , "Placido --, opera singer" , "Placido ... is popular tenor" .)