Cherished rendition of rare duets (9)
I believe the answer is:
treasured
'cherished' is the definition.
(I know that cherished can be written as treasured)
'rendition of rare duets' is the wordplay.
'rendition of' is an anagram indicator (I've seen 'rendition' mean this).
'rare'+'duets'='rareduets'
'rareduets' is an anagram of 'TREASURED'.
(Other definitions for treasured that I've seen before include "Valued" , "Valuable" , "Cherished, held dear" , "Loved" , "Chersihed, held dear" .)