Ask to keep note folded (7)
I believe the answer is:
pleated
'folded' is the definition.
(as in a pleated skirt)
'ask to keep note' is the wordplay.
'ask' becomes 'plead'.
'to keep' means one lot of letters goes inside another.
'note' becomes 'te' (musical note).
'plead' placed around 'te' is 'PLEATED'.
(Other definitions for pleated that I've seen before include "Folded and stitched" , "Folded and sewn" , "Given creases" , "(Garment) with folds" , "With folds sewn in" .)