When the old Mexican guy started playing the donkey jawbone, it became apparent this wasn't your grandpappy's hoedown.

The fiddlers kicked off the jam session with the old Appalachian standard "Cumberland Gap." Then the tune segued into "Dedicado a Joe," a French-Canadian number. That's when the Mexican musicians in their cowboy hats took the cue and joined with their jaranas and guitarras.

That was also the point where Andres Vega Delphin started rattling the teeth of the proverbial jawbone of an ass, providing a clickety-clack beat.

And with that jam session, this multinational, multilingual contingent of musicians may have invented a new musical style by blending Appalachian, Mexican and French-Canadian forms -- AppalMexiNadian? -- and they did it here, Tuesday afternoon, in Roanoke at Jefferson Center.

"It's killer," said Dylan Locke, the center's programming director, as he listened to the musicians jam in a rehearsal studio. "Sonically, it makes perfect sense. They picked up on it immediately."

The musicians are members of three diverse musical groups, all brought to Roanoke to perform at Jefferson Center in tonight's North American Festival of Traditional Arts (yes, the acronym is NAFTA), a concert and tour presented by Jefferson Center and partly funded by a $20,000 grant from the National Endowment for the Arts.

The group received other grants, as well, to cover a weeklong tour that will take the musicians from Virginia to Pennsylvania, New York and Washington, D.C.

Each group plays a specific style within North America's sprawling soundscape. Heidi Clare Lambert and her band AtaGallop play old-time mountain music from East Tennessee.

Grupo Mono Blanco are considered pioneers of son jarocho, an acoustic-based traditional form from Veracruz, Mexico.

Rapetipetam is a seven-person group from Montreal that specializes in fiddle-and-accordion tunes and lots of dancing.

The groups' mission: to marry their styles into a seamless whole, overcome cultural hurdles, break down barriers and all that warm-and-fuzzy "why can't we all just get along" kind of stuff.

"I don't think there's any agenda," said Lambert, who plays fiddle and dances like a true mountain girl, even though she's from California. She played with the late, great Reeltime Travelers before forming her own group.

"Speaking for myself, as a citizen of the United States, I'd like to see us get along with our neighbors a little better."

That process began Tuesday morning, when the musicians met, played and listened during a marathon rehearsal. Early on, the musicians stayed within their own groups, jamming and dancing. By afternoon, they had laid the foundation of a unified show. Not everyone speaks fluent English -- the Tennesseeans do pretty well -- so most of the communication was through music. One musician would show another a little lick on the banjo or jarana. By the end of the afternoon, the Mexicans were picking out "John Henry" and the Americans and French-Canadians were strumming and fiddling "La Bamba."

"You don't go with words when you can saw out, tap out or pick out what you want communicated," Lambert said.

Still, putting together the show in one daylong rehearsal is a monumental task. Mexican dancer Gisela Farias Luna was having difficulty accommodating her steps to the strict tempos of the Montreal group. Lambert struggled to find her timing with Gilberto Gutierrez when the two danced.

Musicians laid back in some places, not wanting to overplay on tunes they did not know very well.

"This is the part I have trouble envisioning, the segue into the hambone," said Ron Thomason, just before he sang an Appalachian ballad and performed a knee-slapping, literally, "hambone" piece in which he sings and keeps a rhythm by slapping his legs.

"It's all similar," said bassist Jorge Pomar. "The rhythms are similar. It's all string instruments. It's fun."