ELI5: Explain Like I'm 5

Circle of fifths

The circle of fifths is a way to show how all the notes on a musical scale go together. It's drawn like a circle so that when you look at it, you can see how the notes go around in a circle. Every note on the scale is next to two other notes that go together in fifths. That means if you start at a certain note and count five notes up or five notes down, it will eventually come back around to its starting point. This circle helps musicians to know which notes go together and to easily understand the relationships between the notes.