Music is written on a set of five lines with four spaces in between them. We call this the staff. Think of it like a ladder that music climbs up and down.
The rungs of this ladder tell you how high or low a sound is. When a note sits low on the staff, it makes a low sound, like a big bear growling. When a note climbs up high on the staff, it makes a high sound, like a tiny bird chirping.
Notes can sit right on a line, so the line goes through the middle of the note. Or a note can sit in a space, tucked snugly between two lines. Every line and every space is a home for a different pitch.
The higher a note sits on the staff, the higher it sounds, and the lower it sits, the lower it sounds. This rule is the secret to reading almost any song.
Musicians all over the world read the staff the same way, so a singer in one country and a singer in another can play the very same tune from the very same page. That is why the staff is such a powerful tool.
Next time you see sheet music, look for the five lines and four spaces. You are looking at a ladder of sound, waiting for you to climb it.