Inside a large rehearsal space with high ceilings, about an hour outside of Barcelona, people were practicing climbing on top of each other to form human towers. The residents of Catalonia have been building these castells for centuries, and while the UNESCO-recognized tradition has changed little over time, the participants that day signed in to rehearsal using an app on their phones. Then the people forming the base of the tower put their feet against those of the participants in front of them and kept their head down for protection. And up the climbers went.

“You can see it on the television and that’s great,” Pablo Molinero-Martinez, a program coordinator for the Smithsonian Folklife Festival, says about the human towers. But taking part in one, as the locals invited him to do that day last year, he adds, is “totally different.” Whereas many athletic teams have less than a dozen participants on a field or court at once, human towers sometimes involve hundreds.

Molinero and his colleagues visited Catalonia, located in northeastern Spain, during a years-long effort to bring the traditions of that region to the Smithsonian Folklife Festival. The Smithsonian Center for Folklife and Cultural Heritage began hosting the festival on the National Mall in 1967. With Molinero as program coordinator, Folklife Center director Michael Mason, Cristina Díaz-Carrera and David Ibáñez curated the festival program, called “ Catalonia: Tradition and Creativity from the Mediterranean .”

“We have a program with a lot of spectacle in it,” says Díaz-Carrera, one of the curators. “There’s fire, there’s giant puppets, there’s human-tower building.” But the event is meant to celebrate the Catalan people who maintain those traditions. “Behind all of those really spectacular things is this really integrated, well-oiled network of people,” she says.

The Folklife Center began working with people in Catalonia, a region that has been seeking independence from Spain, on a language initiative years ago, studying languages historically spoken there. Those contacts led to talks about creating a festival program around the area’s local traditions. Folklife Center staff members made multiple trips to the region to train researchers and meet with individuals that the curators call “tradition bearers.” For the first time in the history of the festival, organizers put out an open call for participants. More than 120 people and groups applied.

Six Catalan musical acts will perform in the evenings, and more performances will happen during the days. The acts represent various Catalan musical traditions, including Catalan rumba, which is derived from flamenco music, and habanera, a form that curators say is experiencing a revival after years of decline.

One of the musical acts is Yacine and the Oriental Groove , consisting of Yacine Belahcene Benet, Massinissa Aït-Ahmed, Gabriel Fletcher and Alexandre Guitart. Based in the Catalan capital of Barcelona, the group describes its sound as “Mediterranean rock,” incorporating North African and Mediterranean musical traditions, as well as genres such as reggae and rock and roll. Emphasizing the Catalan tradition of embracing people from various places and cultures, the group sings in Catalan, French, Spanish and Arabic, as well as Amazigh, a language of indigenous North African people.

The fusion of those sounds comes naturally, according to the band, whose members are from countries including Algeria and Uruguay. “It just comes as it is because we are people from different places that met in this point of the world right now,” says Guitart, the drummer, translating for his bandmates. “So it’s just coming out, it’s just flowing from us.”

Their appearance at the Folklife Festival will be their first time performing in the United States, and they believe people should turn to their music for “more than just to listen.” “We want the people to dance,” Guitart says, translating for the others, “to get this unity, to get this moment that we can forget for a while the dark side and we can focus on the light.”

Also performing is the Catalan duo Maria Arnal and Marcel Bagés , who have been selling out shows in Europe. Arnal, who sings while Bagés plays guitar, says the festival will be her first visit to the U.S. and that she plans to explore Washington’s museums when she’s not busy performing.

Arnal and Bagés released their debut full-length album, 45 cerebros y 1 corazón (45 Brains and 1 Heart) , last year and it has earned acclaim. The Barcelona-based newspaper La Vanguardia described the record as among “the few ‘instant classics’ that, from time to time, alter (for good) the musical panorama.” Spain’s Rockdelux magazine named their previous five-song disc Verbena the country’s best EP of 2016, and Barcelona’s Ara newspaper called them “one of the best things that has happened to Catalan music in recent years.” Their dreamlike music videos have garnered more than 1 million views online.

Arnal says about their sound, “It’s a very strange music, experimental, but can interest people that love traditional music but also people that love electronic music, even pop music.” She adds, “We don’t really work by thinking in genres.”

As Arnal tells it, she grew up in a musical household where her mother would often sing. Arnal went on to study performing arts, anthropology and literature, but she later decided she wanted to pursue her passion for singing. Her anthropology studies came in handy, as that is how she stumbled upon the archives of the late American folklorist and ethnographer Alan Lomax , who traveled the world, including to Catalonia, making field recordings of local folk songs. (Lomax advised Smithsonian festivals.) Those archives helped Arnal and Bagés find their unique sound, and their album incorporates remixes of field recordings.

“My repertoire, it’s somehow based on some of the songs that he recorded in Spain,” she says. “I include other lyrics and I include neo-melodies and things, but the base is there.”

The festival’s evening concerts will also feature the Catalan acts Les Anxovetes , a habanera group featuring women’s voices; the singer-songwriter Alidé Sans ; the improvisation-heavy 10-member group Cobla Catalana dels Sons Essencials ; and Joan Garriga i el Mariatxi Galàctic , a trio that performs rumbero and rumba music. Musicians from other parts of the world will also perform.

Besides the music, the festival lineup includes processions incorporating traditional Catalan elements such as giant puppets, on a scale that curator Díaz-Carrera says has never happened before in Washington. There will also be Catalan cooks who specialize in seafood, meats and other local culinary traditions.

And of course there will be tower climbers—more than 200 of them. But don’t expect the rival groups attending to collaborate. “Our idea was to explore if there was an option to do a human tower together,” Molinero says, “but this is something they have never done and will never do.”

The Smithsonian Folklife Festival will take place daily and most nights from June 27 to July 1, and July 4 to 8.