Chart-topping songs (4)
I believe the answer is:
hits
'chart-topping songs' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for hits that I've seen before include "Pop successes" , "welcome in the theatre world?" , "The sort of strikes" , "Raps - successful recordings" , "In the 60s these were 'groovy'" .)