There's a snag with this type of song (5)
I believe the answer is:
catch
'there's a snag' is the definition.
(I've seen this before)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for catch that I've seen before include "Disadvantage that's hidden" , "Fly in the ointment" , "Good match" , "potential partner?" , "Desirable partner" .)