Sound at the door (3)
I believe the answer is:
rap
'sound at the door' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for rap that I've seen before include "taken by those held to blame?" , "Sort of music" , "Hit - "songs" by Snoop Dogg and Jay-Z, say" , "Form of music with spoken lyrics" , "Knock sharply" .)