Minneapolis native Grant Johnson and Iron Range native Rich Mattson have been performing in the Duluth area since the late 1980s. They formed their duo in 2006, and have released four full-length albums since then, the most recent being 2009’s The Bitter Spills Sing Folk Songs, Vol. 4. Their emphasis on both original and traditional folksongs lends for a rousing performance with rich harmony vocals and inventive guitar work. Tours around the country and regular performances in Duluth and the Iron Range have prepped this duo for a show full of energetic folk rawk.