From Rattle a rare musical gift (3)
I believe the answer is:
ear
'musical gift' is the definition.
(a talented musician has 'the ear')
'from rattle a rare' is the wordplay.
'from' indicates a hidden word.
'EAR' is hidden within 'rattle a rare'.
(Other definitions for ear that I've seen before include "'Give every man thine ..., but few thy voice' (Hamlet)" , "Listener in the cornfield" , "organ with drum" , "Aural appendage" , "See 8" .)