A burglar beating it would be a blow (3)
I believe the answer is:
rap
'a blow' is the definition.
(rap is a kind of blow)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for rap that I've seen before include "Urban music style" , "African-American music in which the lyrics are spoken" , "Pounding" , "Knock, tap" , "talking during musical performance" .)