Hit musical sample from American niece (5)
I believe the answer is:
annie
'hit musical' is the definition.
(I've seen this in another clue)
'sample from american niece' is the wordplay.
'sample from' says the answer is hidden in the clue (a sample of letters from the clue).
'ANNIE' is hidden in the letters of 'american niece'.
(Other definitions for annie that I've seen before include "Musical based on cartoon strip" , "Cartoon strip orphan" , "Name of girl (with gun)" , "-- Lennox, singer" , "Musical about markswoman" .)