Duke Ellington, for example, also included in British editorial (10)
I believe the answer is:
bandleader
'duke ellington for example' is the definition.
(I know this)
'also included in british editorial' is the wordplay.
'also' becomes 'and' (both can mean in addition).
'included in' means one lot of letters goes inside another.
'british' becomes 'b' (abbreviation e.g. in 'BBC').
'editorial' becomes 'leader' (both can mean a type of newspaper article).
'b'+'leader'='bleader'
'and' going into 'bleader' is 'BANDLEADER'.
(Other definitions for bandleader that I've seen before include "Music director" , "Conductor, perhaps" , "He conducted" , "Music supremo" , "Top musician" .)