Making music:

The piano makes a sound when you push a piano key down.

When the key is pushed down, a small hammer hits a string.

The string moves back and forth. The string vibrates.

The string makes a sound. Every key has its own hammer.

Every hammer has its own string.
Each piano string is different. Some string are long.

They make low sound when a hammer hits them. Some string are short.

They make high sound when a hammer hits them.
You can push a key lightly. Then the hammer hits the string lightly.

A soft sound is made.

You can push a key hard. Then the hammer hits the string hard.

A loud sound is made.

Cosme