Produce notes on organ (7)
I believe the answer is:
deliver
'produce' is the definition.
(I know that deliver is a kind of produce)
'notes on organ' is the wordplay.
'notes' becomes 'de' (two musical notes).
'on' says to put letters next to each other (in a down clue, letters appear on others).
'organ' becomes 'liver' (liver is a kind of organ).
'de'+'liver'='DELIVER'
(Other definitions for deliver that I've seen before include "Carry < , and give birth to" , "bear" , "Bring to its destination - rescue" , "Bring into the world - set free" , "Transfer and hand over" .)