I end duet rarely as originally composed? (8)
I believe the answer is:
unedited
'as originally composed?' is the definition.
(unchanged from the original version)
'i end duet rarely' is the wordplay.
'rarely' is an anagram indicator (rare can mean unusual or strange).
'i'+'end'+'duet'='iendduet'
'iendduet' anagrammed gives 'UNEDITED'.
(Other definitions for unedited that I've seen before include "Text that's been unaltered" , "Left as seen" , "Not yet prepared for publication" , "As written, without correction" , "as it was first presented?" .)