"¡A las barricadas!" - Spanish Anarchist song [Anthem of CNT] 

"A las Barricadas" ("To the Barricades") was one of the most popular songs of the Spanish anarchists during the Spanish Civil War. "A las Barricadas" is sung to the tune of "Whirlwinds of Danger" ("Warszawianka"), composed by Józef Pławiński. The lyrics written by Valeriano Orobón Fernández in 1936 were partly based on the original Polish lyrics by Wacław Święcicki.
"The Confederation" referred to in the final stanza is the anarcho-syndicalist CNT (Spanish: Confederación Nacional del Trabajo - "National Confederation of Labor"), which at the time was the largest labour union, the main anarchist organisation in Spain, and from 1936 to 1939 were a major force opposing Francisco Franco's military coup against the Spanish Republic.