A 1970s musical may be heard in this country (6)
I believe the answer is:
greece
'this country' is the definition.
(Greece is a European country)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for greece that I've seen before include "European nation" , "Mediterranean country" , "Hellas is its ancient and modern name" , "in E" , "Country of southeast Europe" .)