Opera in new setting out of doors (4,3)
I believe the answer is:
open air
'out of doors' is the definition.
(I've seen this before)
'opera in new' is the wordplay.
'new' is an anagram indicator.
'opera'+'in'='operain'
'operain' anagrammed gives 'OPEN-AIR'.
'setting' acts as a link.
(Other definitions for open air that I've seen before include "Out-of-doors" , "theatre" , "like Glastonbury gigs" , "concerts?" , "Alfresco" .)