Discuss composer on the radio (6)
I believe the answer is:
handle
'discuss' is the definition.
(thesaurus)
'composer on the radio' is the wordplay.
'composer' becomes 'handel' (George Frideric Handel).
'on the radio' shows a homophone (sound like).
'handel' sounds like 'HANDLE'.
(Other definitions for handle that I've seen before include "Touch, hold, move" , "Feel or manipulate" , "Manipulate; manage" , "Part by which something is held" , "Part to be grasped" .)