Song arranged by Carlo (5)
I believe the answer is:
carol
'song' is the definition.
(carol is a kind of song)
'arranged by carlo' is the wordplay.
'carlo' anagrams to 'CAROL'.
But, I'm not clear how the anagram is indicated.
Can you help me to learn more?
(Other definitions for carol that I've seen before include "Song celebrating the birth of Jesus" , "Girl" , "Joyful song - woman's name" , "See 1" , "Canticle" .)