The Italian turned bitter letters into operatic words (8)
I believe the answer is:
libretti
'operatic words' is the definition.
'libretti' can be an answer for 'words' (I've seen this before). I'm unsure of the 'operatic' bit.
'the italian turned bitter letters' is the wordplay.
'the italian' becomes 'il' (Italian for 'the').
'turned' shows that the letters should be reversed in order.
'letters' indicates an anagram.
'il' backwards is 'li'.
'bitter' anagrammed gives 'bretti'.
'li'+'bretti'='LIBRETTI'
'into' is the link.
Can you help me to learn more?
(Other definitions for libretti that I've seen before include "Opera texts" , "Words" , "score-books?" , "Books" , "Da Ponte's texts" .)