They are trying to stay within the law. The first Pegida hymn was to the same tune as Deutschland uber Alles, which was to the tune of an ancient German hymn. They were criticized for that, even though it was legal. Also, because the hymn mentioned Jesus Christ, it was attacked as being anti-Jewish.
So they wrote another hymn, to another tune, with NO WORDS, just humming. I ask you.
They have a rough row to hoe over there, with no First Amendment and so many PC things being illegal because of their history.