That it falls under the banner of a music festival is startling enough, but tonight's pairing is truly extraordinary. Bonnie "Prince" Billy (Will Oldham), on his first solo tour since 2007, and Mount Eerie (Phil Elverum) are artists of the highest caliber—singular, iconoclastic, unspoiled, and, many years in, every bit inspired as they are inspiring. Each draws from the distinctive musical tradition of their respective homes, Oldham of the golden country-folk of the American South, and Elverum from the elemental indie rock of the Northwest. Each has built dedicated fanbases while largely eschewing commercial and corporate opportunity. Each employs wry senses of humor, yet cultivates tangible emotional connection with deceptively straight talk. Both too, are insatiable students of the craft, artists outside of music, and prolific collaborators. Speaking of collaborations, Elverum provided backing vocals on Bonnie "Prince" Billy's stirring "Go Folks Go," in 2010. Whether or not they'll share the stage tonight is anyone's guess. As Oldham relayed through his publicist, "Who knows about the collab possibilities?" ANDREW R TONRY Also see My, What a Busy Week!