Horst-Wessel-Lied
The "Rotfront" ("Red Front") was a reference to the Rotfrontkämpferbund, a communist militia tied to the Communist Party of Germany (KPD). It was common for Nazis' Sturmabteilung and Communists' Redfront to attack each other in violent street fights, which eventually grew into full-scale battles after 1930. "Reaction" was a reference to the conservative parties and the liberal democratic German state of the Weimar Republic period, which made several unsuccessful attempts to ban the SA. "Servitude" means what the Nazis saw as Germany's "servitude" to the Treaty of Versailles of 1919, which imposed huge reparations on Germany and deprived her of her colonies and territory along her eastern border.