Supercilious about organ-playing skill (8)
I believe the answer is:
arrogant
'supercilious' is the definition.
(thesaurus)
'about organ-playing skill' is the wordplay.
'about' indicates putting letters inside.
'playing' is an anagram indicator.
'skill' becomes 'art' (both can mean a talent).
'organ' is an anagram of 'rogan'.
'rogan' going inside 'art' is 'ARROGANT'.
(Other definitions for arrogant that I've seen before include "Self-important and overbearing" , "Disdainful" , "Cocky" , "Overweening" , "Cut a design on metal" .)