Broadcast simple melody (3)
I believe the answer is:
air
I believe this clue is a double definition.
'broadcast' is the first definition.
(synonyms)
'simple melody' is the second definition.
(air can mean a melody or tune)
(Other definitions for air that I've seen before include "If it's hot, it's boastful" , "Tune or aura" , "Tune; mien" , "Light breeze" , "Broadcast; mien" .)