Unusual male singing voice framed in female singing voice (8)
I believe the answer is:
falsetto
'unusual male singing voice' is the definition.
(falsely high male singing voice)
'framed in female singing voice' is the wordplay.
'framed' becomes 'set' (as in framing or setting in a frame).
'in' is an insertion indicator.
'female' becomes 'f' (abbreviation).
'singing voice' becomes 'alto' (type of singing voice).
'f'+'alto'='falto'
'set' going within 'falto' is 'FALSETTO'.
(Other definitions for falsetto that I've seen before include "Artificial upper register of a male voice" , "High singing method" , "Aritifical upper register of male voice" , "Male voice above the normal range" , "A forced high singing voice" .)