Selecting a ballad that’s cheap (5,3,1,4)
I believe the answer is:
going for a song
'cheap' is the definition.
(I've seen this before)
'selecting a ballad' is the wordplay.
'selecting' becomes 'goingfor' (going for is a kind of selecting).
'ballad' becomes 'song' (I've seen this before).
'goingfor'+'a'+'song'='GOING FOR A SONG'
'that's' is the link.
(Other definitions for going for a song that I've seen before include "Available very cheap" , "Available at a bargain price" , "Selling very cheaply" , "Being offered very cheaply" , "Being sold very cheaply" .)