Lois disturbed by duet performed in isolation (8)
I believe the answer is:
solitude
'isolation' is the definition.
(I know that solitude is a type of isolation)
'lois disturbed by duet performed' is the wordplay.
'disturbed' indicates an anagram (the order of letters is disturbed).
'by' means one lot of letters go next to another.
'performed' indicates anagramming the letters.
'lois' anagrammed gives 'soli'.
'duet' is an anagram of 'tude'.
'soli'+'tude'='SOLITUDE'
'in' is the link.
(Other definitions for solitude that I've seen before include "Lone state" , "Privacy" , "Lack of company" , "Absence of company" , "Isolation, loneliness" .)