The Chanchona Tipica de El Salvador, a string and percussion group from the war-scarred eastern region of El Salvador, will be doing double duty this year at the Smithsonian Folklife Festival. Not only will they entertain many of the 1 million visitors who swarm over the annual 10-day event, but they will also be participants in a new in-depth exploration of Latino music by the Smithsonian Institution.

"Nuestra Musica: Music in Latino Culture" is a research project that will be officially launched at the festival later this month and continue for four years. It is a joint effort of the Smithsonian Center for Folklife and Cultural Heritage, the managers of the festival, and Smithsonian Folkways Recordings, the museum's award-winning label.

The idea was born out of the organizers' affection for Latino music, as well as an acknowledgment of the growing Latino population in the United States. In addition, the Smithsonian has been working to pay more attention to Hispanic culture after public criticism that it was neglecting a diverse population and its achievements.

Daniel Sheehy, director and curator of Smithsonian Folkways and a longtime scholar and performer of mariachi music, took on the task of shedding light on Latino music's various genres.

"People do talk about the Latino demographic, but unfortunately more people pay more attention to that than the diversity within the demographic. We wanted to give an idea of the Latino grass-roots culture," he said, sitting in his office at Gallery Place, a wall full of bomba, plena and tango criollo CDs behind him. "The commercial festivals, where you hear some of the music, pick the acts with the broadest appeal. In the Folklife Festival program we want to get below the veil of popular culture."

Starting June 23, the festival will showcase musicians from the United States and Latin America who will perform California-based mariachi traditions; roots sounds from Veracruz, Mexico; Dominican merengue; Texas-Mexican conjunto; and vallenato, accordion music from Colombia. The art of improvisation with musicians, poets and songwriters will be acknowledged in what Sheehy calls a La Pena setting -- a type of jam session.

After his research, Sheehy hopes that groups like Chanchona of El Salvador will find a new audience. "The chanchona is a big pig, a sow, and they have adopted that word for the bass. They are from San Simon, where there was a tremendous amount of fighting, and their songs tell about love, tragedy and leaving to go to Nuevo Jersey," Sheehy said.

Sheehy knows the term "Latino music" is much too general and inadequate, but he hopes the audience realizes its diversity and depth.

"We are trying to create moments and present the real-life issues you can see and hear in the music, the change from rural to urban life, the journey from El Salvador to Washington," he said.

As an undergraduate at UCLA, Sheehy was recruited to play with a mariachi band after his rhythm and blues outfit disbanded. Sheehy, 57, has been playing the trumpet with mariachi groups ever since and worked for the National Endowment for the Arts for 22 years. He joined the Smithsonian in 2000.

The festival programs will also include dance and makers of llanero harps, maracas and sacred drums, as well as plenty of food.

Because of Latino population growth in the Washington region, Sheehy's recent fieldwork for the Folklife Festival was often close to home. The Fraternidad Folklorica Sangre Boliviana are from Bolivia and Arlington.

Members of another group, Los Tecuanes, reside around Manassas, but they choreograph work native to Puebla, Mexico. "There are 32 members, and they do a village dance drama that is performed on sacred holidays. They start dancing at 4 a.m. in front of All Saints Church in Manassas on December 12, the feast of the Virgin of Guadalupe. They emphasized that what they do is a devotional," said Sheehy, who signed the group for an appearance.

The Nuestra Musica project will return to the Folklife Festival for three more years, but it is designed to have a full life beyond the festival as well.

Some of the artists will record their compositions in studios, and interviews and research will be added to Smithsonian Web sites. The recording of CDs, to total 25 eventually, is already underway, providing a foundation for the now-official project. Since 2002 10 recordings have been issued and two garnered Grammy nominations. "Capoeira Angola 2" by Grupo de Capoeira Angola Pelourinho and "Jibaro Hasta el Hueso" by Ecos De Borinquen were nominated this year.

For more than a decade, officials at the Smithsonian have been tackling how to give greater exposure and equity to Latino expression in the arts, science and research. The gaps in this treatment were frankly admitted by officials in 1993, who then ordered a study of the role of Hispanics in areas the Smithsonian covers. The result was a stinging report that accused the Smithsonian of "benign neglect." In 1997 the museum set up the Smithsonian Center for Latino Initiatives, a coordinating office for issues ranging from employment to exhibitions.

Meanwhile, supporters of a National Museum of the American Latino have introduced legislation on Capitol Hill to establish a facility that, if successful, could join the Smithsonian family.

The music project, says Sheehy, will cost $1 million a year, with initial support coming from the Smithsonian Latino Initiatives Fund, the NEA, Anheuser-Busch and Delta Air Lines. Sheehy says potential additional funders and the public will discover something to support through the project.

"There's a lot of music out there, but it lives in a parallel universe to mainstream popular music. So we are trying to use the National Mall and Independence Day to bring out the Hispanic contribution to America."

Daniel Sheehy curates the Smithsonian's project to explore Latino music's diversity."We wanted to give an idea of the Latino grass-roots culture," says Daniel Sheehy, the curator of the Smithsonian's four-year music project.