Popular songs have a striking effect on military display (3,6)
I believe the answer is:
hit parade
'popular songs have a' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.
'striking effect on military display' is the wordplay.
I cannot really understand how this works, but
'striking' could be 'hit' (synonyms) and 'hit' is present in the answer.
'display' could be 'parade' (parade is a kind of display) and 'parade' is present in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for hit parade that I've seen before include "Selling CDs" , "Pop charts" , "Top-selling numbers" , "list of winners" , "Those once charting" .)