Musical flower (5)
I believe the answer is:
poppy
I believe this clue is a double definition.
'musical' is the first definition.
(like pop music)
'flower' is the second definition.
(poppy is a kind of flower)
(Other definitions for poppy that I've seen before include "Flower of cornfields" , "Cornfield flower" , "girl, > rather like Daddy?" , "catchy records like this" , "Scarlet flower worn in Remembrance" .)