Complex sentence: Vorwärts! schmettern die hellen Fanfaren ("Forward! Forward! Blare the bright fanfares") was a marching song of the Hitler Youth, which was also their banner song.
Split into simpler sentences: Vorwärts! schmettern die hellen Fanfaren ("Forward! Forward! Blare the bright fanfares") is a marching song. It was used by the Hitler Youth, which was also their banner song.