Aca Seca Trio, an Argentine musical group, creates music that caresses the soul. The sound is neither jazz nor folk. Maybe its both.

The three artists - Juan Quintero (acoustic guitar and vocals), Andrés Beeuwsaert (piano and vocals) and Mariano Cantero (percussion and vocals) - make their Spoleto Festival debut tonight with a show in the Cistern Yard that features original songs informed by various musical traditions of South America. The concert is part of the group's first U.S. tour.

Aca Seca Trio found its way into the festival like so many other artists who participate in the Wells Fargo Jazz Series. Michael Grofsorean, director of the series since 1980, heard a sample two years ago of Beeuwsaert collaborating with Brazilian pianist Eloisa Fernandez, a festival veteran. She led him to Aca Seca Trio's tunes, including "Paloma."

"After I heard 'Paloma', they had me," Grofsorean said. "There's a power in vocal music that transcends understanding the lyrics and I think opera is the more widely understood manifestation of that. It's the same for these guys, or any Brazilian that I bring to the festival."

Speaking in Spanish over Skype, Quintero explained the group's musical style, which employs Argentinian chacarera.

Chacarera is the folkloric rural counterpart to the familiar urban Tango. A rhythmic dance form, it often features guitar and percussion, voice and violin. Aca Seca's approach results in soft-spoken lullabies and ambient earthy music.

"There is an instrument that is not easy to find, el bombo leguero, which is a very big drum made from goat leather and wood," Quintero said. "It is played a lot in rhythmic folklore in Argentina and is very hard to find, so we are bringing our own."

The three musicians crossed paths in their early music career while studying composition and orchestral direction at Universidad Nacional de la Plata. Each of them was developing his own sound, incorporating Argentine folk, classical music and jazz. They formed Aca Seca Trio in 1998, chosing the name as a kind of joke. (It means dried poop in the dialects of northern Argentina).

The trio has produced three records, "Aca Seca" (2003), "Aviendo" (2006) and "Ventanas" (2009). They have since worked on their own projects with Latin American artists from all over the continent.

"The particular thing about the sound of the group is that the three of us come from very different parts of Argentina," Beeuwsaert said. "Juan is from Tucuman in the northwest part of Argentina where he grew up with folkloric sounds."

When the three regroup to perform as a trio, they almost always silence their instruments and sing something a capella. Quintero said the three of them understand the power of vocals, and when the people in the last rows can hear them without amplification, they give the audience an unexpected harmonious gift.

"At the time of playing, we don't really think of our academic backgrounds or of rock or jazz, it's more of a game that we give ourselves to, fully, with our whole body," said Quintero. "If we want to sing we sing, and if we want to play an instrument in a certain way, not traditional to the chacarera, then we just do it."

Alejandra Acuna is a Goldring Arts Journalist from Syracuse University.