Why row merited after a lot of work producing operetta (3,5,5)
I believe the answer is:
the merry widow
'operetta' is the definition.
(operetta by Franz Lehar)
'why row merited after a lot of work' is the wordplay.
'after a lot of work' is an anagram indicator (letters must be worked into a new form).
'why'+'row'+'merited'='whyrowmerited'
'whyrowmerited' with letters rearranged gives 'THE MERRY WIDOW'.
'producing' is the link.
(Other definitions for the merry widow that I've seen before include "Franz Lehar operetta" , "show" .)