Think of it as all the fun of an outdoor music festival without the crowds—or the outdoors.

In late September, nearly 3,000 people logged on to their Minecraft accounts and got ready to party. The world-building video game has been often used to create larger than life sculptures, buildings, and artworks, but internet-collective Thwip Gang had bigger ideas.

After hosting a Minecraft-based “Birthday Party” for one of their members back in May, the Thwip Gang got to work organizing a full-scale concert completely within the gaming platform. With no more promotion than a few tweets on the organizers’ personal Twitter pages, Coalchella drew in 27,000 listeners over its 8 hours across various streaming platforms. (“Coalchella” because in Minecraft one mines coal, among other minerals. Just go with it.)

The free festival required nothing more than a Minecraft account to attend and drew some big name headliners like ANAMANAGUCHI and Electric Mantis. The musical lineup came together somewhat serendipitously—in an interview with the blog Melting of Age, one of Coalchella’s creators and Thwip Gang collaborator, Umru Rothenberg said, “It was a very random process of just asking whatever friends came to mind or saying ‘this person would be cool’ and checking if anyone was mutuals with them.”

After entering, festival goers arrived at the stage of their choosing — REDBLOCKS or BEDROCKS — and tuned into a livestream on the broadcast audio website Mixlr. Just like IRL, when the performer’s avatar took the stage, the crowd of block people burst into life and the music started. The digital attendees then started dancing and the in-game chat flooded with commentary about the concert.

As if a full-scale two-stage concert “venue” isn’t enough, the Thwip Gang also scattered brands and logos thoughout the virtual site. An IHOb restaurant, a giant Bass Pro Shops Pyramid, and an overhead IKEA blimp were among those featured. Only there was a catch: None of the brands knew their logos were being used for the event — they were mostly plastered around Minecraft as cultural touchstones.

Ad Age reached out to some of the brands referenced in the festival. Stephanie Peterson, head of communications and merchandise at IHOP said, “We’re thrilled that our fans got in on the fun and took it to a new level, creating an epic virtual IHOb restaurant in Minecraft.” A spokesperson for Bass Pro Shops added, “Virtual worlds are interesting but our primary goal is to inspire everyone to get outside and connect with nature.”

At this stage at least, the advertisements are mostly tongue-in-cheek—but having actual sponsor messages is not completely out of the question—and now they have proof-of-concept.

“What will always be most important to me is…that [brands] are not influencing, openly or otherwise, what I am experiencing in any way,” says co-organizer Robin Boehlen, “We can coexist with brands without them becoming controlling.”

Co-organizer Braden Wolfe adds “preserving that [grassroots] presence is really important to what we’re trying to accomplish; creating a universally accessible music event free of region or monetary restriction.”

None of the artists actually paid (or were paid) to play. “All of our impressions were purely organic and the results are a testament to the importance of putting forward unique, inclusive ideas,” explains Max Schramp, one of the festival’s organizers.

Here’s a sample of some of the buzz surrounding the event:

Rothenberg was thrilled by the response and contributed the success of the event to the Internet’s ability to bring people together, both physically and virtually. “Most of us grew up with the internet as a major part of our lives and personally some of my best friends are people I met on Soundcloud and Twitter. An event like this where so many of us from all over the world could hang out together alongside our favorite artists in a virtual space is a literal dream for this kind of community.”