Copy made where nothing replaces end of simple song? (5)

I believe the answer is:

ditto

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'copy' is the definition.
(I've seen this before)

I don't understand the remainder of the clue.

(Other definitions for ditto that I've seen before include "Two small marks indicating the same again" , "Do alternative" , "Duplicate" , "In lists, the same again with two small marks" , "Mark used to indicate repetition" .)

I've seen this clue in The Times.

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