European agreement on snoring being music (4)
I believe the answer is:
jazz
'being music' is the definition.
(I've seen this before)
'european agreement on snoring' is the wordplay.
'european agreement' becomes 'ja' (I am not sure about this - if you are sure you should believe this answer much more).
'on' says to put letters next to each other (in a down clue, letters appear on others).
'snoring' becomes 'zz'.
'ja'+'zz'='JAZZ'
Can you help me to learn more?
(Other definitions for jazz that I've seen before include "Improvised style of music" , "Form of music" , "Humph's music" , "Musical genre" , "Ronnie Scott's music?" .)