I loved the beginning music

You mean the intro? That is - in general - a very strong thing in the movie.
Its a german childrens song, of little Hans walking lonesome into the world.
Interwoven with pictures of strung out german soldiers far away from home in Russia, and some battle scenes.

"Hänschen klein ging allein
In die weite Welt hinein.
Stock und Hut stehn ihm gut,
Ist gar wohlgemut..."

Love it, especially chilling with footage of children, Nazis & Hitler.

https://www.youtube.com/watch?v=2sqwkpiFg4c