Music festival - the second one in Rome The Christians listen to (4)
I believe the answer is:
pope
'the second one in rome the christians listen to' is the definition.
I can't judge whether this definition defines the answer.
'music festival' is the wordplay.
'music' becomes 'pop' (pop music is a kind of music).
'festival' becomes 'e' (I am not sure about this - if you are sure you should believe this answer much more).
'pop'+'e'='POPE'
Can you help me to learn more?
(Other definitions for pope that I've seen before include "freshwater fish" , "English poet, d. 1744" , "church leader in Rome" , "Pontiff" , "Vatican head" .)