As the owner of Eau Claire’s one and only hip record store, Billy Siegel is always happy to promote his midsize city’s big indie-rock music festival, Eaux Claires. There’s one problem this year, however.

“I normally stock up on all the artists who are playing at it,” said the Revival Records shopkeeper, “but I don’t know who they are.”

Siegel is in the same boat as fans thinking about buying passes to the fourth annual musical campout in west-central Wisconsin: Eaux Claires organizer Justin “Bon Iver” Vernon and his team are making the unprecedented move of keeping their July 6-7 lineup a secret.

While the lineups for other summer music fests have all been revealed by now — including that weekend’s competing Basilica Block Party in Minneapolis — Eaux Claires has yet to announce a single act among its 2018 performers. And it sounds as if it won’t name names until fans are streaming onto the festival grounds overlooking the Chippewa River, about 90 miles east of Minneapolis.

In an interview earlier this month, the Grammy-winning Eau Claire native said the reason they’re keeping the lineup under wraps is that he wants attendees “to be surprised for once.

“We’re not trying to be tricky, not trying to be cool,” said Vernon, who hasn’t even revealed if he will perform a Bon Iver set this year (he didn’t at last year’s fest).

“We’re not trying to sell more tickets. In fact, it’s definitely not helping us. I don’t care about that. I care about surprising people — and having people remember that their art and their music is not just a commercialized commodity.”

In truth, Vernon and his team actually have been quite tricky about the lineup. They have left hints in various podcasts, tweets and Instagram posts, often with scrambled or abbreviated audio tracks by the artists. Fans have combed through the clues and assembled their guesses in various fan forums online, including an in-depth, hyper-nerdy Reddit thread.

Some of the most-cited performers so far include: Patti Smith, Sharon Van Etten, Phoebe Bridgers, Kevin Morby and Ho99o9 (all first-timers at the fest); the National (whose guitarist Aaron Dessner co-curates Eaux Claires with Vernon); Sufjan Stevens, Moses Sumney, Anäis Mitchell, Low and Marijuana Deathsquads (who’ve all played it before), and Frances & the Lights (who weirdly seem to play every year).

Asked about the validity of those lists, however, Eaux Claires representatives declined to confirm or even comment on the guesswork.

Some fans aren’t too happy about being left in the dark. David Hodorowski, an Eau Claire native living in New York, posted this comment on the festival’s Facebook page: “Where’s the lineup? I know it’s super indie-cool to keep it a secret, but seriously … not gonna get my friends [from] NYC there blindly.”

“It’s a horrible marketing strategy,” wrote Eau Claire resident Greg Kernkamp, “and disrespectful to the artists they are booking if they have no way to market the gig for themselves.”

Some fans are amused by the decision, though. One even suggested that organizers make a guess-the-jellybeans kind of contest and see who can estimate a list nearest to the full lineup.

“If it’s a specific artist who you come for, this festival isn’t for you,” wrote Michigan fan Ryan Christopher. “This is a festival for people who trust in others and accept it.”

Despite his uncertainty going into the festival, the Revival Records owner Siegel said he appreciates the artistic statement Vernon is trying to make.

“It complicates things business-wise, but creatively I think it’s a cool idea,” said Siegel. “It’ll make it a different kind of experience for everyone who attends, and maybe it’ll get people into bands they didn’t already know.”

Vernon said the no-name idea is an extension of an unnamed, free-form music fest he co-organized in 2016 at the Funkhaus studio complex in Berlin with members of Poliça, the National and other musicians. One of that festival’s producers, Mary Hickson, is also working on Eaux Claires.

“Berlin changed everything for sure,” Vernon said, quoting Dessner, his partner in both festivals: “We’ve been doing this stuff on the side, this stuff that isn’t at all about who we are or what press we’ve gotten or whatever. It’s just about music.”

“Berlin solidified that we really need to put some muscle into it,” Vernon added.

That musical experiment eschewed the hallmarks of most fests. No headliners, no schedule. The only merch: a single T-shirt. Throughout, musicians teamed up across bands and genres.

“We want to disrupt normality,” Vernon said. “Like rock ’n’ roll in general, you know what I mean?”

When: July 6-7.

Where: Foster Farms, 3443 Crescent Av., Eau Claire, Wis.

Tickets: $177-$355/two-day pass, $165 campsite.

Website: eauxclaires.com.