Refrain from song unavailable (3,3)
I believe the answer is:
lay off
'refrain' is the definition.
(thesaurus)
'song unavailable' is the wordplay.
'song' becomes 'lay' (lay is a kind of song).
'unavailable' becomes 'off' ().
'lay'+'off'='LAY-OFF'
'from' acts as a link.
(Other definitions for lay off that I've seen before include "Dismiss, usually for economic reasons" , "Terminate employment, or cease to bother" , "Make redundant; hedge (bet)" , "Stop - cease to employ" , "Give over!" .)