Concerning mum going out on the road and returning as a percussionist (7)
I believe the answer is:
drummer
'percussionist' is the definition.
(drummer is a kind of percussionist)
'concerning mum going out on the road and returning as a' is the wordplay.
I cannot really see how this works, but
an anagram of 'mum' is 'umm' which is present in the answer.
'concerning' could be 're' (both can mean on a particular topic) and 're' is present in the remaining letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for drummer that I've seen before include "Timpani beater" , "eg Buddy Rich" , "Traveller in America" , "Gene Krupa, say" , "Type of percussionist" .)