Writing in Aesop adaptation works on the stage (6)
I believe the answer is:
operas
'works on the stage' is the definition.
'operas' can be an answer for 'works' (I have seen 'Musical works' mean 'operas' so perhaps 'works' could also mean 'operas'). I am unsure of the 'on the stage' bit.
'writing in aesop adaptation' is the wordplay.
'writing' becomes 'r' (one of the traditional three R's of education).
'in' indicates putting letters inside.
'adaptation' is an anagram indicator.
'aesop' is an anagram of 'opeas'.
'r' inserted within 'opeas' is 'OPERAS'.
Can you help me to learn more?
(Other definitions for operas that I've seen before include "Dramas set to music" , "eg Faust, Salome" , "Musical plays" , "Dramatic works set to music" , "La Traviata, Aida" .)