There was one song that might have changed the world a little. "We Shall Overcome".

No one here has defined what "changing the world" means.

When school kids all over the world sing "This Land Is Your Land", are they being educated some how? Does that education change them?

obviously, Dick, "This machine kills fascists" was meant in a metaphorical sense.
it was Woody expressing his views on Hitler. Did Woody's songs change someone's mind?
How do we know? Maybe some dead fascist ideas trailed behind his guitar.

Does music change the world? If a song changes one person's mind, does that constitute
"changing the world"? Or does a song/lyric just reinforce what a person already believes?

Heres what I think. A finely written song contains elements such as specificity, pictures,
dialogue sometimes, craft with successful rhymes and stanzaic consistency, singability (not so complex as requiring a coloratura to sing it), a consistent central idea, an ability to have the listener "own" it, an attractive melody, a focus so that you know who is singing the song (in the song) and why, variety and contrast, and impels not only the listener but the singer. It's content can vary from all ranges of emotional experience.

When an audience hears a song like this, they changed. Since audiences are part of the world and are all over the world, then some audiences over the world are changed.
Does this change the whole world? Does it change "some worlds"?

Frank Hamilton