Usually our mind is filled with many kinds of ignorant thoughts, and that makes the mind seem ugly. If you practice hard and gradually take away ignorance, you get enlightenment. Everybody has goodness, or song, already in their mind. One way to easily see this is by going to a movie where a good character is battling a villain. If the good character and the others suffer a lot at the hands of the scoundrel, then everybody watching the movie feels upset.
Nobody wants the good person to die.
The anxiety we feel is the innate goodness we already have in us. This mind appears. So that's goodness. It comes from our nature, our true nature. Myself and all beings are not different, and are never separate.