Good to stop awful song (5)
I believe the answer is:
dirge
'song' is the definition.
(dirge is a kind of song)
'good to stop awful' is the wordplay.
'good' becomes 'g' (abbreviation).
'to stop' indicates putting letters inside.
'awful' becomes 'dire' ('dire' can be a synonym of 'awful').
'g' going into 'dire' is 'DIRGE'.
(Other definitions for dirge that I've seen before include "Threnody" , "Keen; lament" , "A depressing number" , "dreary tune" , "Mournful chant" .)