Final issue of two notes (4)
I believe the answer is:
fate
'final issue' is the definition.
(I've seen this before)
'two notes' is the wordplay.
'two notes' can mean two replacements for 'note'.
'note' becomes 'fa' (fourth note in sol-fa notation: doh, ray, me...).
'note' becomes 'te' (musical note).
'fa'+'te'='FATE'
'of' is the link.
(Other definitions for fate that I've seen before include "Predestination" , "Final issue" , "Inevitable destiny" , "One's lot" , "Clotho, Lachesis or Atropos" .)