note is a kind of music notation, which is used to indicate the sound level and duration in the melody or rhythm of music. Notes are usually represented by graphic symbols, which commonly include circular symbols, English letters and various additional symbols. Basic notes usually include the following types:

1. Whole note: Whole note is the most basic note, which is represented by circular symbols. It represents that the pitch and duration of a note occupy the whole bar time. In the 4/4 beat, a beat can be represented by a whole note.

2. Dichotomy note: Dichotomy note is a note with half the duration of the whole note, and its symbol is a hollow circle plus a straight line. In the 4/4 beat, one beat can be represented by two binary notes.

3. Quarter note: Quarter note is a note with a duration of one quarter of the whole note, and its symbol is a solid circle plus a straight line. In the 4/4 beat, one beat can be represented by four quarter notes.

4. Octave note: An octave note is one-eighth the duration of a whole note, and its symbol is a solid circle plus a straight line and a tail to the right. In the 4/4 beat, one beat can be represented by eight octaves.

In addition, there are sixteenth notes, thirty-second notes, sixty-fourth notes and other notes with different durations. Their characters, shapes and additional symbols are also different, but they are all basic symbols used to express music melody.