Broadcasting very happily? (2,3)
I believe the answer is:
on air
I believe this clue is a double definition.
'broadcasting' is the first definition.
(broadcasting on the air)
'very happily?' is the second definition.
(I've seen this before)
(Other definitions for on air that I've seen before include "now showing" , "Live broadcast" , "In the process of broadcasting - floating aloft?" , "In the process of broadcasting on radio or TV" , "Broadcasting live" .)