What began as a military coup on the 25 of April that year, soon coupled with an unexpected civil resistance movement as people took to the streets in droves to protest the Estado Novo regime under dictator António Salazar. A peaceful revolution, with barely any shots fired by the depleted Portuguese military, it was the beginning of a new democratic country and an end to their Colonial War.

Two things have embedded themselves into the mythology of that day. Firstly, the revolution is often referred to as the ‘Carnation Revolution’ due to the vast amount of these flowers handed to soldiers to be placed in their guns and lapels by restaurant worker Celeste Caeiro - initially as a symbolic gesture from the flowers her restaurant had planned to hand out that day and later taken up by flower-sellers around Lisbon who began handing out their own.

Although this is the enduring image, it's not how it all began. The revolution was actually initiated by a cue that played through the radios to the population and military. It wasn’t a rallying-cry or inciteful speech - it was Zeca Afonso’s Grândola, Vila Morena. Beamed out from Rádio Renascença at 12.20am, the second secret signal of the day informed rebel troops to begin taking over strategic spots around Lisbon.

At the time, Afonso was banned from public radio due to subversive activities. An educated folk singer, whose reputation as a cantor began during his days of study at the University of Coimbra, he quickly gained recognition for his socially conscious and politically tainted lyrics. Frequently performing his works in Communist strongholds, and an avid supporter of the Labour Union movement, the bookish Afonso, with his thick-rimmed glasses, was transformed into a countercultural icon of an increasingly urban Portugal.

After a tour, branded as a pilgrimage of Portugal to promote his new works, Afonso was arrested and reprimanded in Caxias prison for 20 days by Portugal’s secret police, tasked with tackling dissidents. Not long after his release, he performed a sellout show at Lisbon’s Coliseu, culminating in an impassioned rendition of Grândola, Vila Morena. In the audience were members of the military’s dissident Armed Forces Movement who, only one month later, would initiate the revolution and decide upon this song as the second cue.

With a life involved indirectly in politics, having seen Portugal as a citizen, teacher and musician, both in urban and rural areas - as well as her colonies - Afonso carved a path through the country's dictatorship offering an alternative vision for the country. Yet, still, by chance, a song with a socially conscious message became the inadvertent anthem for a country’s transition into democracy - one that’s still sung at political protests and events around Portugal today and will continue to each year on the 25th of April.