the five parallel horizontal lines used to record notes are called staff. The five lines of the staff and the space formed by the five lines are calculated from bottom to top. If a musical work is written on several lines of staff, then these lines of staff should be connected by a hyphen.

the higher the position of the sound on the staff, the higher the sound, and the lower the position of the sound, the lower the sound, but how high is it? How much lower? But I can't be sure. To determine the pitch of a staff, you must use clef to indicate it. When clef is recorded on a certain line of the staff, it gives this line a fixed level name and height, and also determines the level names and heights on other lines or intervals.

There are three kinds of clefs commonly used:

The G clef indicates the G of a small group, which is recorded on the second line of the staff, also called the treble clef; In addition, there is something written on the first line, called the old French treble clef.

the f clef indicates the f of the small group, which is recorded on the fourth line of the staff, also called the bass clef; There is also a note on the fifth line called double bass clef.

the clef c indicates a group of small characters, which can be recorded on any line of the staff. At present, the C clef adopted is the C triple clef (also known as alto clef), which is used for viola and sometimes trombone. C clef for four lines (also called alto clef) is used for cello, bassoon and trombone. Other c clefs are generally less used. The purpose of using many clefs is to avoid too many lines, so that it is more convenient to write and read the spectrum. All kinds of clefs can be used alone or in combination, such as the big score table composed of high and low clefs.