Not every band is capable of producing powerful music, the kind that brings old souls to tears and young ones to their feet. But the Shoemaker Brothers, four siblings from Shelton, Washington, are not only capable of producing it—it is their only product. Theirs is the kind of music that evokes emotion; many an audience has fallen in love with their passion for and their commitment to their art. Their soulful sound is founded on classical strings and cultivated by American folk but grounded in a rock ‘n’ roll sensibility that keeps it fresh. The Brothers’ warm, homegrown vocals showcase lyrics that deal with issues that touch many American lives. In early January, they released a self-titled album before embarking upon a tour that will take them to the nation’s four corners.

Consisting of Samuel on the violin, Nathanael on the cello, Daniel on the viola, and Gabriel on the violin, the Brothers grew up as four of seven children—all of wh...