Hit by musician (6)
I believe the answer is:
rapper
'musician' is the definition.
(I know that rapper is a type of singer)
'hit by' is the wordplay.
'hit' becomes 'rap' (I've seen this in another clue).
'by' becomes 'per' (I've seen this in another clue).
'rap'+'per'='RAPPER'
(Other definitions for rapper that I've seen before include "Entertainer who recites rhythmically to music" , "MC" , "Performer chanting rhyming lyrics to African-American music" , "One who knocks" , "Eg, Eminem" .)