Preserving the legacy of spirituals is a particular mission of the Heritage Signature Chorale, which was founded in 2000, but the vibrant a cappella group takes into account contemporary tastes.
"Our arrangements have a more contemporary, very exciting flavor," Thurston says. "Some sound very gospel in style, with a percussive element."
A different contemporary choral sound is in store next week, when the young group Only Men Aloud contributes to the festival's Welsh component.
The group is all about preserving the tradition of male choral singing in Wales that, founding director Tim Rhys-Evans says, "sprang out of the Industrial Revolution, when families were large and incomes weren't. Men would get together and sing. It was a way of socializing."
Rhys-Evans became concerned that Welsh choral groups were getting grayer and all-male ensembles getting fewer, so he formed Only Men Aloud in 2000.
"I don't believe in ring-fencing music," Rhys-Evans says. "We'll do everything from [17th-century Italian composer] Allegri to AC-DC, I guess."
That stylistic variety helped Only Men Aloud take top prize last summer on a popular British TV contest called Last Choir Standing, and attract several recording contract offers (Rhys-Evans chose one from Universal, and a recently released first CD has sold 300,000 copies).
The ensemble is likely to be a hit of the folk festival when it performs July 2.
"There will be a lot of Welsh traditional music and all manner of other stuff in the concert, to show what we do," Rhys-Evans says. "I feel we have a duty to make our concerts as entertaining as possible. We are not afraid to access our camp side."
Whether harmonizing on a Welsh hymn or kicking up their heels to "Don't Rain on My Parade," Only Men Aloud makes quite the distinctive statement.
"I think it helps some people realize that choirs don't have to be what they thought choirs were," Rhys-Evans says.
Helping people discover something new about something old - that's pretty much the whole point, and lasting appeal, of the Smithsonian Folklife Festival.
If you go
The Smithsonian Folklife Festival runs Thursday through Sunday and July 1 through July 5 on the National Mall. Call 202-633-7484 or go to festival.si.edu.
