Musician — one with a racket (7)
I believe the answer is:
fiddler
I believe this clue is a double definition.
'musician' is the first definition.
(fiddler can informally mean a violinist)
'one with a racket' is the second definition.
(fiddle can mean a racket or fraudulent scheme)
(Other definitions for fiddler that I've seen before include "Violinist (on the 11?)" , "Great musical ''....... on the roof''" , "Type of crab; one on the Roof" , "String player" , "Violinist (colloq.)" .)