Chinese dynasty, something bright and good (4)
I believe the answer is:
sung
'chinese dynasty' is the definition.
(I've seen this before)
'something bright and good' is the wordplay.
'something bright' becomes 'sun'.
'and' means one lot of letters go next to another.
'good' becomes 'g' (abbreviation).
'sun'+'g'='SUNG'
(Other definitions for sung that I've seen before include "Chinese dynasty; uttered melodiously" , "Celebrated dynasty" , "Performed vocally; Chinese dynasty" .)