The Humboldt Folklife Festival rolls on toward its conclusion in a couple of days with another evening in the Dell'Arte amphitheater. Tonight’s theme is “Bluegrass and Beyond,” with performances by Ruby Ruth and Mule Ranch, Elderberry Rust Band and Cadillac Ranch. The bands play in that order, with a 6 p.m. start time and $10 admission price, minus two bucks if you are a member of the Humboldt Folklife Society.