Setting for a cello composition (6)
I believe the answer is:
locale
'setting' is the definition.
(I know that locale is a type of setting)
'a cello composition' is the wordplay.
'composition' indicates anagramming the letters (letters arranged or composed in a different order).
'a'+'cello'='acello'
'acello' with letters rearranged gives 'LOCALE'.
'for' acts as a link.
(Other definitions for locale that I've seen before include "Setting" , "Area connected with event" , "where something happens" , "Place associated with particular events" , "Spot" .)