The national anthem of East Germany, "Auferstanden aus Ruinen" (English: Risen from Ruins). The Youtube includes many images of the DDR. ¡Qué Ostalgia! It reminds me of Good-bye, Lenin!, one of my favorite movies because it includes not one, but two national anthems in their entirety ("Auferstanden" and "Das Lied der Deutschen").
Anyway, the "fun fact" about "Auferstanden" is that it has exactly the same beat as "Das Lied der Deutschen," that is, each can be sung along with the other melody (the music for "Auferstanden" was by Hanns Eisler). Also, since the author of the lyrics (Johannes Becher) neglected to anticipate the incoming Cold War, the lyrics ("Germany, united fatherland!") had to be left behind somewhere in the '50s, leaving just the tune. Best other line: "If we unite as brothers, we will defeat the enemy of the people."