I wrote that song for my wife, and it's what some guy who's sitting under a tree would be singing to the woman of his life, telling her how wonderful she is. To me, that's more lasting than something that sounds like it belongs on a movie soundtrack.
I think that we all know what evil is. We have a sense of what's evil, and certainly killing innocent people is evil. We're less sure about what is good. There's sort of good, good enough, could be better - but absolute good is a little harder to define.