Song about it duo ruined in concert halls (9)
I believe the answer is:
auditoria
'concert halls' is the definition.
(I've seen this before)
'song about it duo ruined' is the wordplay.
'song' becomes 'aria' (aria is a kind of song).
'about' means one lot of letters goes inside another.
'ruined' indicates an anagram.
'it'+'duo'='itduo'
'itduo' with letters rearranged gives 'udito'.
'aria' placed around 'udito' is 'AUDITORIA'.
'in' acts as a link.
(Other definitions for auditoria that I've seen before include "Spaces for audiences" , "lecture theatres" , "Locations for houses" , "Theatre areas for spectators or listeners" , "Theatres, concert halls" .)