Two notes from operatic heroine (4)
I believe the answer is:
mimi
'operatic heroine' is the definition.
'two notes' is the wordplay.
'two notes' means two substitutions for 'note'.
'note' becomes 'mi' (as in 'do re mi').
'note' becomes 'mi' (as in 'do re mi'**).
'mi'+'mi'='MIMI'
'from' is the link.
(Other definitions for mimi that I've seen before include "Tragic heroine" , "Puccini heroine" , "unfortunate sewer" , "Puccini's seamstress" , "Her tiny hand was frozen (Puccini)" .)