Some modest piece of poetry (3)
I believe the answer is:
ode
'poetry' is the definition.
(I've seen this before)
'some modest piece' is the wordplay.
'piece' indicates the answer is hidden within the clue.
'ODE' is hidden in the letters of 'some modest'.
'of' is the link.
(Other definitions for ode that I've seen before include "poetry" , "Sung poem" , "A poem celebrating person or event" , "Literary work" , "Poetic composition" .)