Song and dance commercial (6)
I believe the answer is:
ballad
'song' is the definition.
(ballad is a kind of song)
'dance commercial' is the wordplay.
'dance' becomes 'ball' (ball is a kind of dance).
'commercial' becomes 'ad'.
'ball'+'ad'='BALLAD'
'and' acts as a link.
(Other definitions for ballad that I've seen before include "Lay, narrative song" , "Simple song or poem" , "Love song" , "Slow sentimental song" , "delivered by singer" .)