Tries very hard to produce tunes (7)
I believe the answer is:
strains
I believe this is a double definition.
'tries very hard' is the first definition.
(I've seen this before)
'tunes' is the second definition.
('strain' can be a synonym of 'tune')
'to produce' acts as a link.
(Other definitions for strains that I've seen before include "Stresses and - -" , "Melodies" , "Tries very hard" .)