Someone once said that jazz and cinema are the only art forms that Americans do better than anyone else in the world. It's a sweeping -- and presumably tongue-in-cheek -- statement that ignores many American-perfected musical styles, bluegrass music among them. And while, generally speaking, Americans may not revere cultural traditions with the same fervor as European and other cultures, there are enclaves of preservationists who work to uphold musical traditions while recasting them in a more modern light. The Lyons-based Open Road Bluegrass Band, Sunday, April 30, at the Mountain Sun Brewery in Boulder, is a group of five traditionally trained players who do just that. The players perform bluegrass standards from Bill Monroe and the Stanley Brothers, as well as original tunes penned with a loyalty to the style of those and other bluegrass masters. Open Road's style separates it from other local groups that incorporate bluegrass into more free-form, jammy musical meanderings; its emphasis on authenticity marks it as a revivalist, rather than revisionist, outfit. The approach seems to be working: Last year the band was invited to open for acts such as the Del McCoury Band and Peter Rowan. Sounds like this band is heading down the right road.