Harmony and Discord are the two main characters in this game. In order to play this game, you need to use both hands. Put your right hand on the arrow keys on your keyboard, and put your left hand on the W and S keys on the keyboard. As the song goes, notes will appear. You have to push the correct arrow key at the correct time to match the arrows that are scrolling on the screen. You can hold the arrow key down instead of pushing it in time. However, you also have to keep up with how high and low the notes are going. Push W to make the notes go up and S to make them go down.