Musical animated movie — saucy stuff (6)
I believe the answer is:
catsup
'saucy stuff' is the definition.
(another spelling of 'ketchup')
'musical animated movie' is the wordplay.
'musical' becomes 'Cats' (Andrew Lloyd Webber musical).
'animated movie' becomes 'Up' (Pixar film).
'cats'+'up'='CATSUP'
(Other definitions for catsup that I've seen before include "Relish" , "something saucy from US" .)