To hear Amy Ray tell it, Justin Vernon might be a little off his rocker.
"But we're very flattered," the Indigo Girls co-founder quickly added with a laugh.
Ray and her musical partner of 30 years, Emily Saliers, learned a few years ago that Wisconsin's Grammy-winning Bon Iver bandleader and indie-cool tastemaker is a major fan of the activist folk duo.
Vernon is so into the Indigo Girls, in fact, that he not only booked them alongside the likes of Boys Noize, the National and Doomtree at his inaugural Eaux Claires Music & Art Festival, but also asked them to perform their 1994 album "Swamp Ophelia" in its entirety.
"It's my favorite album of all time," Vernon emphatically told us. "And they're still probably my favorite act of all time. I've never let up on them. I've never needed a fashionable reason to like them. I find them to still be highly underappreciated."
Talking by phone a week ago from a tour stop in Mobile, Ala., Ray said she and Saliers are excited by the prospect of playing to "the cool kids" July 18 at the festival in Vernon's native Eau Claire, Wis. "We don't get asked to the Lollapalooza and Coachella kind of festivals anymore," she said.
By sharp contrast, the duo will also perform to their faithful Twin Cities flock in the more familiar confines of the Minnesota Zoo the night before, July 17. ("We love everything about that place — except the bugs.")
Between now and then, Ray said, they will probably rehearse one song per day from "Swamp Ophelia" with their band to be ready for the special Eaux Claires gig. Only about five of the album's 11 songs have remained part of their live repertoire.