If it gives you any perspective on how much this New Jersey six-piece values spontaneity, the band dove into its first studio venture a mere three weeks after forming and recorded everything live except for the backing vocals. In the seven years since, Railroad Earth has gotten tighter and honed its songcraft while maintaining its off-the-cuff sense of adventure. XM host Felton Pruitt's once described Railroad Earth as what "American Beauty"-era Grateful Dead would have sounded like had they been using bluegrass instrumentation. True enough, but Railroad Earth also brings a decidedly modern twist to the proceedings and hits a new level of vocal harmonizing. Meanwhile, violinist Tim Carbone gives the music a spacey dimension with his liberal use of effects, a great complement to the roots foundation.

Railroad Earth plays Friday, May 2, 7 p.m. at the German House Theatre, 315 Gregory Street. $17.50. 232-1900.