San Basilio de Palenque is a small town on Colombia's Caribbean coast that's nicknamed "the first free town of the Americas." This is because, in the early 17th century, African slaves that had been kidnapped from their homelands and brought to the nearby port of Cartagena escaped and founded "palenques" (simple settlements, fenced-off with sticks, or "palos" in Spanish) in the mountains now known as Montes de María, where they could live free.

There, they created a mix of the various African cultures and languages that they brought with them, that survives to this day. Palenqueros, as their inhabitants are called, have not only a special language, (Ri Palenge, which is a Spanish, Portuguese and Bantu pidgin), a special type of music (heavily infused with African percussion), and a special identity in the Colombian census. They also share a special history.

The first palenques were led by Benkos Biohó, a former nobleman from what is now Guinea-Bissau who had been taken to Cartagena in the late 16th century. Biohó organized an army of "maroons," or escaped slaves, and established a small army and an intelligence network to help new slaves escape. In the palenques, he was known as "king."

This, of course, upset the Spanish authorities that ruled the territory that would eventually become Colombia, as they saw the escaped slaves as lost property, and only recognized their own king. But, unable to defeat the very well-organized maroons, in 1605 the Governor of Cartagena offered Biohó a peace treaty. Under the treaty, which the palenque king accepted, the Palenqueros would be considered free and entitled to the use of their land in exchange for agreeing to not receive nor aid more escaped slaves.

The Spanish violated the peace treaty in 1621 when they captured Biohó as he walked freely around Cartagena and hanged him, arguing that he was becoming too powerful. After that, the various palenques kept warring with the Spanish for decades, all the while reassembling, regrouping, and relocating. But they remained strong, free communities that eventually frustrated the Spanish authorities enough to grant them freedom officially. This happened in 1713 when, with the help of the bishop of Cartagena, the Spanish authorities legally granted the Palenqueros freedom, the right to a territory, and the right of self-government, thus becoming "the first free town of the Americas."

After this, the community rebuilt their palenque where it currently stands, and named it San Basilio, according to legend, because a statue of Saint Basil that was passing through town got stuck there, and the Palenqueros took it as a good omen.

San Basilio de Palenque still stands, but it is now a corregimiento, or a small district, of the Colombian municipality of Mahates, in the Bolívar department. It was here that

Simón Mejía, one of the founders of the internationally famous Colombian band Bomba Estéreo, arrived in 2007, for a trip that would link him with Palenque for years to come. Mejía tells the story like this:

"Those were Bomba Estéreo's early years, and I was researching Afro-Colombian music for the band. So I went to the Barranquilla carnival, because I wanted to research folkloric music there. But my friend Santiago Posada and I decided to stop in San Basilio, since we had heard so much about it. We were there for a weekend and we got to discover first-hand the incredible universe of San Basilio that we had had the chance to know through Lucas Silva's Palenque Records, the percussionist Batata, and so on. We thought it was incredible, so we decided to begin a musical project there."

The friends won a Prince Claus grant from the Netherlands, and with that they were able to spend three months in 2008 in San Basilio building a music studio that the community there could use. It was their first—and still only—professional music studio. They organized some workshops to teach the people there how to run the studio, and in 2009 published a compilation of Palenquero music with the English label SoulJazz.

The album, called "Jende Ri Palenge" (or "People of Palenque" in Ri Palenge), was accompanied by a documentary film detailing the process of building the studio and recording the album.

In 2017, almost ten years after having helped build the studio, Mejía saw an opportunity to document again what had happened since then. He and Simón Hernández pitched a new documentary to Red Bull for their series "Searching for Sounds," in which musicians travel to remote places to learn more about their music. But, instead, Mejía would go back to San Basilio and the studio, to see what had changed since it was built.

In the documentary, he's joined by Franklin "Lamparita" Tejedor, a member of a prominent Palenquero musical family, and a musician in his own right, who formed the self-styled "forest techno" band Mitú with former Bomba Estéreo member Julián Salazar. Mejía met Tejedor on that first trip to San Basilio, and he ended up becoming key in building the music studio, as well in many other collaborations.

In the documentary, they discuss a Palenquero instrument called "marímbula"—a caja-sized lamellophone (like a mbira, or a kalimba, but big enough to sit on it) used to provide bass lines—at length and, briefly, how the music of San Basilio has changed since the building of the studio.

Since finishing the second documentary, Mejía has been working in other projects that have highlighted Afro-Colombian musicians, in particular in their recent collaboration with Arcade Fire. Win Butler, lead singer of the popular Canadian band, invited Bomba Estéreo to join them in their tour at the end of 2017. While touring Latin America, Butler proposed Bomba Estéreo to record an Arcade Fire cover in Spanish.

Bomba Estéreo remixed and covered "Everything Now" with the help of Los Gaiteros de Ovejas, a traditional ensemble from northern Colombia that plays traditional Afro-Colombian drum and gaita-flute music. The three groups joined on stage when Arcade Fire toured Bogotá last December.