Musical drama extremely tiresome work (7)
I believe the answer is:
operate
'work' is the definition.
(synonyms)
'musical drama extremely tiresome' is the wordplay.
'musical drama' becomes 'opera' (I've seen this before).
'extremely' means to remove the middle letters (only the extremes of the word are used).
'tiresome' with its middle taken out is 'te'.
'opera'+'te'='OPERATE'
(Other definitions for operate that I've seen before include "Make to work" , "(Of machine) function" , "Work, run" , "Work, function" , "Work as a surgeon" .)