Agree to set out notes on a line (3,3)
I believe the answer is:
see fit
'line' is the definition.
Although both the answer and definition are verbs in their base form, I don't see how they can define each other.
'agree to set out notes' is the wordplay.
'agree' becomes 'fit' (synonyms).
'to' means one lot of letters go next to another (I've seen this in other clues).
'set out notes' becomes 'see' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'fit' after 'see' is 'SEE FIT'.
'on a' is the link.
Can you help me to learn more?
(Other definitions for see fit that I've seen before include "Consider suitable" , "Consider to be proper or desirable" , "Perceive in good shape, so choose to do?" , "Think suitable" , "Want" .)