Finding dance music jolly (9)
I believe the answer is:
discovery
'finding' is the definition.
(thesaurus)
'dance music jolly' is the wordplay.
'dance music' becomes 'disco' (type of dance music).
'jolly' becomes 'very' (I've seen this in other clues).
'disco'+'very'='DISCOVERY'
(Other definitions for discovery that I've seen before include "Bay in southeast Australia" , "Something newly found" , "Find - Scott's ship" , "Thing found (or the finding)" , "Sailing vessel" .)