Broadcast good music regularly on sailor's unseen instrument (3,6)
I believe the answer is:
air guitar
'broadcast good' is the definition.
I don't know anything about this answer so I cannot judge whether this works.
'music regularly on sailor's unseen instrument' is the wordplay.
I cannot quite understand how this works, but
'music' could be 'air' (air is a kind of music) and 'air' is located in the answer.
'instrument' could be 'guitar' (guitar is a kind of instrument) and 'guitar' is found in the answer.
This accounts for all the letters.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for air guitar that I've seen before include "Imaginary stringed instrument" , "Instrumental object that's non-existent" , "Imaginary instrument that one pretends to play" , "Just imagine playing this" , "Imaginary instrument played by rock fans!" .)