Paganini is to be played without 'pop' symbols (8)
I believe the answer is:
insignia
'symbols' is the definition.
I don't understand the rest of the clue.
(Other definitions for insignia that I've seen before include "Emblems of rank" , "marks" , "Badge of membership" , "Badge or emblems of office" , "I sign in a funny way to get badges or emblems" .)