10 entertained by duet playing close to disco's DJ (6)
I believe the answer is:
tuxedo
'dj' is the definition.
(I've seen this before)
'10 entertained by duet playing close to disco's' is the wordplay.
'10' becomes 'x' ('x' can be a synonym of '10').
'entertained by' means one lot of letters goes inside another (I've seen this in other clues).
'playing' indicates an anagram.
'close to' says to take the final letters (the close/ending of).
The last letter of 'disco' is 'o'.
'duet' with letters rearranged gives 'tued'.
'x' put inside 'tued' is 'tuxed'.
'tuxed'+'o'='TUXEDO'
(Other definitions for tuxedo that I've seen before include "American DJ" , "American dinner jacket" , "An American monkey-suit" , "Garment" , "Dinner jacket (US)" .)