In J.C. Geiger’s YA novel The Great Big One (Little, Brown, July), a small group of friends in coastal Oregon united in their passion for music and dedication to disaster preparedness happens upon a musical mystery. While monitoring the radio airwaves late one night, the crew picks up the most amazing piece of music they’ve ever heard. Determined to find its elusive source, they embark on an epic journey.

It wasn’t until Geiger was nearly done writing his book that he realized the story was calling out for its own soundtrack. So, he made one. And now readers can experience the Great Big One playlist in a very old-school way: on an exclusive, limited-edition audiocassette—yes, cassette tape—featuring new rare and unreleased tracks from Fruit Bats, Rhiannon Giddens, the Hold Steady, Matt Hopper, David Lowery, Pink Martini, and more than 10 other bands. (See a trailer here).

The mixtape mimics a late-night radio broadcast, and listeners can hear clues embedded in the static and the songs that will lead them on a musical treasure hunt to various prize stashes (custom jewelry, art, concert tickets) hidden at indie bookstores, and a few libraries, across the U.S. To obtain one of the cassettes while supplies last, readers who purchase The Great Big One at an independent bookstore can present proof of purchase on Geiger’s website. Once all the tapes have been claimed, they will be mailed out at the same time.

For music lover Geiger, this unusual tie-in turned out to be a perfect fit, even if he might not have realized it at first. “Often you don’t necessarily know why you’re compelled to write something,” he said. “It’s only later that you are reminded by somebody or something, that there was a seed planted years and years ago that led to this creation years later.” Once The Great Big One was almost finished, he started to think about the inspiration behind it and he had a revelation: “Oh my gosh, I’ve been doing this my whole life—chasing music and art, the things that really speak to me,” Geiger said. “From my teenage years up until now, which has involved me doing some really ridiculous things like, you know, flying all the way to Minneapolis from Eugene, Ore., in an insane dust storm with a three-year-old child to go see the Hold Steady play.”

He recalled an anecdote from his childhood when he became obsessed with a standout guitar riff he heard as interstitial music on MTV’s The Real World. “It was one of those riffs that just makes you jump up,” he recalled. He had to wait for the episode to re-air so he could record the music snippet—on his father’s Dictaphone. Then he headed to the local mall. “I went through like six stores, asking the employees, ‘Have you ever heard this riff?’ ” Geiger said. He hit paydirt at Musicland, where the staffers went outside to round up their resident music guru from his smoking break. “He came shambling in, and when I played the riff for him, he said ‘It’s either Cracker or Motorhead.’” At 12 years old, Geiger couldn’t afford to buy both CDs, so he gambled and bought the Cracker one and the employees put it on in the store. “It was the first riff on the first song of that album—“Teen Angst (What the World Needs Now)”—playing through the Musicland speakers,” Geiger said. “Yeah, it was a huge win.”

Initially planning to create a Great Big One mixtape just for his family and friends, Geiger took a cue from his novel and decided to seek out unreleased or rare songs that aren’t easy to find. Then he made the leap to find recording artists. “A book for me is always just an excuse to reach out to other people and make connections and collaborate with other artists,” he said. “I thought, ‘What if these bands that I love had weird tracks or demo tracks or stuff they wanted to put in the world but don’t have a place for it to fit?’ ” The first person Geiger reached out to was David Lowery, the front man for Cracker. “I wrote him this giant letter, telling him the mall story,” he recalled. Lowery said yes. And Geiger? “I jumped around in my yard! I totally freaked out.”

Once Lowery was on board, Geiger soon had other artists happy to join the project. “These musicians I love, they also love each other,” he said. With the song lineup coming together, Geiger needed to craft the rest of the soundscape to design the mixtape as a radio broadcast. He also recruited his now 10-year-old son as a contributor. “We would go out to the Oregon coast,” Geiger noted. “When the sun goes down, the AM radio band kind of expands in this crazy way because of the ionosphere,” he explained. “We thought it was the coolest thing ever. We bought little Walkmans with cassette tapes and radio receivers and we would go out and harvest sounds. We would just record snatches of interesting sounds, and sometimes it was a song. But a lot of times, it was just bizarre static sounds, the way static kind of ripples and has these interesting contours and pitches.”

After whittling down more than 15 hours of recorded audio, Geiger hired a voice actor to play the part of the DJ, a character who also appears in the book. Geiger also worked with a few audio engineers to ensure high quality. “I want it to be as good as it can be, as authentic as it can be,” he said. “It’s kind of terrifying to produce a project with your heroes on it, because you don’t want to mess it up.” Finally, National Audio Company in Springfield, Mo., the largest manufacturer of cassettes in the country, is producing an undisclosed number of copies. Though contract and legal negotiations with artists’ representatives were sometimes tricky, and Geiger made this project a labor of love—out of his own pocket—he said, “It was 100% worth it.”

The decision to focus on indie bookstores for the treasure hunt part of the tie-in comes “from the heart,” Geiger said. “This is not an anti-Amazon or anti-chain thing,” he added. “It’s much more that I have seen so many independent bookstores suffering, along with the rest of us, during the pandemic. And independent bookstores have saved my life. They are the places that I’ve gone to write, when I couldn’t write at home. I discovered probably the most impactful writing group in my life at an independent bookstore. They do so much community building in a way that we desperately need right now. I really wanted to do something that got people out of the of point-and-click mode.”

Since The Great Big One focuses largely on “connecting with people and places,” Geiger said, “I want to encourage people to get back out and explore their surroundings. If they go buy one book there, then maybe it’s more likely they buy another one at that particular store, or they at least think about it. That ties into the book, which is really about seeking and chasing and the wonder and delight of finding things, or even just chasing things that you believe in.”

Early response to the tie-in from booksellers and readers has been encouraging and Geiger noted that he couldn’t be more satisfied with how things have turned out. “What an amazing way to reach out to your heroes and, in a strange way, collaborate with them on something that hopefully makes the world a more interesting place,” he said.