Excellent band broadcasting (6)
I believe the answer is:
airing
'broadcasting' is the definition.
('air' can be a synonym of 'broadcast')
'excellent band' is the wordplay.
'excellent' becomes 'ai'.
'band' becomes 'ring' ('ring' can be a synonym of 'band').
'ai'+'ring'='AIRING'
(Other definitions for airing that I've seen before include "Broadcast" , "Exposure" , "Broadcasting" , "excursion" , "Ventilating, say a grievance" .)