A cello playing in the vicinity (6)
I believe the answer is:
locale
'the vicinity' is the definition.
(I've seen this in another clue)
'a cello playing in' is the wordplay.
'playing' is an anagram indicator.
'in' is an insertion indicator.
'cello' is an anagram of 'locle'.
'a' inserted into 'locle' is 'LOCALE'.
(Other definitions for locale that I've seen before include "where something happens" , "Area connected with event" , "Setting" , "Place (of an event)" , "Place associated with particular events" .)