Based on public (electronic and printed) secondary sources, this work provides some background on the influence that the Spanish Republican song of the times of the Civil War and the subsequent anti-Franco resistance had on the political culture of the Chilean left of the century. XX. It is postulated that this cantoral aspect played a notorious role in at least three areas: first, promoting and strengthening the adhesion of sectors of the national left to the Spanish democratic and republican cause; second, strengthening the internationalist emancipatory perspective of various militant and non-militant groups; and, third, acting as a precedent for the development of the political-musical movement that will accompany the transforming project of the Unidad Popular.