Here's an audio link to El pueblo unido jamás será vencido performed live at a solidarity concert in Helsinki in January 1974 by Quilapayún together with the Finnish song group Agit Prop:



And here's a story behind the song:

At the time of the Chilean coup d'etat in the fall of 1973, Quilapayún were in Finland. Soon after the incidents of the first nine-eleven, a solidarity concert was arranged at the Old Student House in Helsinki. The concert started with one of the members of Quilapayún announcing from the stage that they had just become refugees having heard that there was no return for them to Chile.

Another Chile solidarity concert was then arranged in January 1974 at the Helsinki Exhibition Hall with Quilapayún together with Agit Prop performing in front of a full house including our then President Mr. Kekkonen. That was my first time ever to hear El pueblo unido jamás será vencido... (continua)