What is the meaning of the word "note"?

Definitions:

a brief written record noun
- I made a note of the appointment.
a characteristic emotional quality noun
- it ended on a sour note
a comment or instruction usually added noun
- Their notes were appended at the end of the article.
a notation representing the pitch and duration of a musical sound noun
- the singer held the note too long
a piece of paper money, especially one issued by a central bank noun
- The buyer peeled off five onethousandzloty notes.
a promise to pay a specified amount on demand or at a certain time noun
- I had to cosign their note at the bank.
a tone of voice that shows what the speaker is feeling noun
- There was a note of uncertainty in my voice.
make a written note of verb
- I noted everything the teacher said that morning.
notice or perceive verb
- I noted that someone was following me.
observe with care or pay close attention to verb
- Take note of this chemical reaction