Go all the way down in Home Waters, then all the way to the right. That is the Song Cave. Inside, explore everything until you come to a statue with four symbols underneath. Right-click on the statue to see the door you need to open with the song created by these symbols. Travel to the spiral door; inside, you will learn the bind song by touching the blue crystal all the way to the right.
Good luck!
The first song is not used for saving, unless you mean defending. Right-click on the red crystals to save.
