Rearranged recital to include new instrument (8)
I believe the answer is:
clarinet
'instrument' is the definition.
(clarinet is a kind of instrument)
'rearranged recital to include new' is the wordplay.
'rearranged' indicates anagramming the letters.
'to include' indicates putting letters inside.
'new' becomes 'n'.
'recital' with letters rearranged gives 'clariet'.
'clariet' enclosing 'n' is 'CLARINET'.
(Other definitions for clarinet that I've seen before include "that works off wind" , "Music maker" , "Wind instrument made from Clare tin" , "Musical wind instrument as played by Benny Goodman" , "member of orchestra" .)