Judge recording to be without opening catchy tune (6)
I believe the answer is:
jingle
'catchy tune' is the definition.
(I've seen this before)
'judge recording to be without opening' is the wordplay.
'judge' becomes 'j'.
'recording' becomes 'single'.
'to be without opening' means to remove the first letter.
'single' with its initial letter taken away is 'ingle'.
'j'+'ingle'='JINGLE'
(Other definitions for jingle that I've seen before include "Ditty" , "Memorable slogan/tune" , "Short slogan/tune" , "Sound of shaken coins" , "Tune for advertisement" .)