‘Welcome to Cahuita town, welcome one and all,” Walter Ferguson sings on the song Cahuita Is a Beautiful Place, offering an invitation to drink some rum and listen to calypso in this corner of Limón, Costa Rica. Its charming lyrical bounce and layered guitar sounds like the work of more than one man, although it is his work alone – and a song that might never have been heard if not for a project aimed at locating the thousands of one-of-a-kind cassettes that Ferguson recorded at home for friends and visitors wanting to take home a piece of this “beautiful place”.

In the run up to Ferguson’s 100th birthday in May, his son Peck (the 10th of Ferguson’s 11 children) and Swiss calypso fan Niels Werdenberg have spent two years on a labour of love: the Walter Gavitt Ferguson Tape Hunt. Their goal is to track down these lost gems, digitising songs that, in 2018, the Costa Rican government designated part of the country’s cultural heritage.

Founded by Jamaican fishermen and farmers who migrated through the Port of Limón in the mid-19th century, Cahuita, with its oceanside national park, has grown into a place that tourists might call a best-kept secret. Even within the country, the Limón region flies under the radar. “It has been pushed aside due to racial prejudice,” says Costa Rican musician and researcher Manuel Monestel. Racism in the country meant that Afro-Costa Ricans were not welcome in the capital, which has resulted in the black population living primarily in Limón.

Ferguson was born in Panama, but his family moved to Cahuita when he was a toddler; with a Jamaican-Costa Rican mother and a Jamaican migrant father, he is a proud Costa Rican. Peck says that Ferguson’s mother always thought her son had the talent of a calypsonian: he reportedly composed his first calypso in 1939, when he was 20, after learning clarinet and guitar while working in a store in Cahuita. He toured the country as a member of a band called Los Miserables in the 60s, but by the 70s farming and faith became his main focus. Composing and playing music became a hobby.

I speak to Ferguson from his home via video call. The sharp centenarian can no longer play, but he speaks vividly of his process and prolific 20th-century output. “As we go around every day, we see different movements,” he says. “That is what causes me to make every day. I see something new, and I make a song for it.”

Each song documents the history of his people. Monilia details the infestation of a devastating fungi that attacked crops in the mid-70s, forcing locals to sell their land or switch their focus to the growing tourism industry. “Monilia,” he sings, “you come to stay and all you bring is hungry belly.”

Cahuita itself is brought to life as well. There’s Bato the builder and his Cabin in di Wata; in Bombero, a domestic fight ends with a husband setting the house on fire. One Pant Man tells of racial discrimination: “She went and told the authority / Telling them I’m a foreigner. / They came with gun and artillery / Compelling me to show them me cedula [identification].”

Walter Ferguson pictured in 2017. Photograph: Nathalie Vigini

Monestel says Cahuita’s history is embedded in Ferguson’s melodies themselves. “It has roots in the calypso from Trinidad and Panama,” he says. “You can track the influences of mento from Jamaica, but I believe the calypso in Limón has its own profile.” By the end of the 70s, Ferguson had begun to capture these musical narratives using a portable cassette recorder, sharing the results with family and friends.

Anthropologist Paula Palmer made the area her home from the early 70s through to the 90s and was one of the lucky people who had received some of Ferguson’s bespoke recordings. “He is a wonderful, generous, and talented human being,” she says. “I don’t remember exactly when Mr Gavitt started giving me cassette tapes, but I treasured them both then and now.”

In 1979 she was contacted by US musicologist Michael Williams, who wanted to meet and record the calypsonian. Equipment was sent ahead, and he travelled overland from El Paso, Texas to Cahuita: “The journey nearly destroyed me,” he says. “It was all worth it.” One recording session was released – it is the only Costa Rican contribution to the Smithsonian Folkways collection – while another did not see the light of day until recently.

The Folkways record increased Ferguson’s reach. With the growth of tourism in Cahuita, more people wanted to meet the calypsonian, and he made more and more tapes, never keeping copies for himself. Neighbours would spread the word, Peck recalls. “If somebody wanted a tape, he would send one of us to the store to get a blank cassette and he would fill it up with song. And each time somebody came, he would need to sing and record again.” Ferguson personally sold these audio postcards from Cahuita through the 90s, but his production eventually petered out. As Ferguson says on an interlude from the Babylon album: “When I sing now, I get tired.”

Others now sing the King of Calypso’s songs. To celebrate Ferguson’s centenary, Monestel brought together artists from 16 Latin American countries, who developed arrangements of compositions for full band, providing their own interpretations, sometimes translating the lyrics. “Even though he is talking about local issues, there is a universal characteristic,” says Monestel. “One of the hardest things is making funny songs that transmit a serious, profound message, and he can do that.”

An example is You Cannot Bathe a Puss, one of the recovered songs, which couches a message about human limitation in a description of his neighbour Ida trying to wash her cat: “No matter how you clever, no matter how you smart, you cannot bathe a puss!” What makes Ferguson more remarkable, says Monestel, is that he “became well known internationally without leaving the little town of Cahuita. He has never performed his calypsos in San José [the capital]. Not even in Limón.”

One of the rediscovered cassettes. Photograph: Niels Werdenberg

Ferguson’s music made it to Switzerland by way of two albums recorded in the early 00s, Babylon and Dr Bambodee. Werdenberg knew that these albums only scratched the surface of the calypsonian’s oeuvre. In 2017, he and his family visited Cahuita, hoping to get the chance to meet Ferguson. Staying at the family’s business, the Cabinas Sol y Mar lodgings, made this possible and, through conversations with Peck, a shared ambition developed: “He said he had been tracking down tapes and trying to convert them to digital to save the legacy of his father,” says Werdenberg. “That’s when I really started to get into this project.”

He estimates that they’re looking for about 200 songs. Since they started reaching out online, they’ve found 25 original tapes, bringing the total number of compositions to 60. Some were found during a renovation in Vancouver, some in the US, and others closer to home across Costa Rica. Peck and Werdenberg have compiled two collections, titled Legendary Tape Recordings, each track painstakingly cleaned and processed to keep the originals alive. The background sounds of chickens and children – or dogs seemingly singing along, as on Canchis Canchis – remain, Ferguson’s voice and guitar always in the forefront. The first volume received rave reviews, the second volume is released this month, and there’s already a third in the works. Physical copies tend to sell out instantly.

It’s not surprising: Ferguson’s sound is infectious. He’s a wonderful storyteller and songwriter, using just enough repetition to encourage listeners to sing along. He will extol his own talents to a creole calypso bounce, admire the Caribbean vegetable staple callaloo, praise a neighbour’s ingenuity, recount a run-in with a ganja dealer, all with a charm that shows why his tapes were kept and cherished for so long. “The people praise me plenty about the music,” Ferguson tells me. “The rhyming, the way I rhyme the words. I say, as the time goes on, people come to love the calypso more.” And there is more to love: it just needs to be found.

• To participate in the tape hunt: walterferguson-tapehunt.mozello.com.