Genie, I agree with you that the tune is similar to 'Die Lorelei.' No doubt the movie makers figured that Lorelei was a tune many non-Germans would recognize. (Ode to Joy would have been better known, but that would be sacriligious.)

I watched the sequence on YouTube, and I find it smarmy and slick. Hindsight is always smarter than everything else.

The author of the 'die Lorelei' was Heinrich Heine, who opposed despotism and nationalism, but the movie industry doesn't want to talk about Germans like that. Horror sells better than courage.