From what I can tell, the song chorus best known across all of Hispanic culture, both in Iberia and the Americas, is probably that of Cielito Lindo. Since I learned it some years ago, I can't help thinking it to myself anytime anyone says more than one "Ay!", which is fairly often. The chorus goes like this, which I won't bother to translate, since the Wikipedia page does such a good job:
Ay, ay, ay, ay, Canta y no llores, Porque cantando se alegran, Cielito lindo, los corazones.
Properly performed, it should sound something like this:
Nora understands the meaning of more than half of this chorus. She knows "canta" (sing) and she definitely understands "no llores" (don't cry). I'm not sure if she comprehends that "porque" means "because", but I think she really might have an understanding that "cantando" is another form of the verb "to sing", even if she doesn't know what a gerund is. The last line is the hardest, and she rarely actually makes it that far.
Thus, without further ado, I present to you Nora's debut music video performance, the mariachi classic, Cielito Lindo...