In relation to music
, someone who takes music already written and prepares it for performance in either the piece's original medium or in another medium altogether.
An example of the former would be Quincy Jones
taking a song he's written and popping out lead sheet
s for the back up band; in this, the form or presentation has not changed. An example of the latter would be taking Le Sacre Du Printemps
and consolidating it down so that two pianist
s can play it. The form and intention are the same but the method of presentation is now different.