When BTS sang Coldplay’s “Fix You” on MTV Unplugged Presents: BTS in February, fans expressed a desire to see the two groups collaborate. Six months later, their wish has finally come true.

The South Korean superstars will appear on the British band’s upcoming album Music of the Spheres, which will be released on October 15. Their collaboration, a song called “My Universe,” will drop earlier than that, on September 24. It was written by both groups and produced by Swedish musician Max Martin.

When he appeared on the American talk show The Kelly Clarkson Show, Coldplay frontman Chris Martin revealed some details about the song and what it was like to work on it with BTS.

“We don’t believe in boundaries or separation of anything, really, so the song ‘My Universe’ is about someone being told they can’t love a certain other person, or can’t be with this race, or they can’t be gay—whatever it might be. And we thought it would be good to sing it with BTS because maybe we’re not supposed to be together. It turned out to be one of the most fun things ever. I even went to Korea to be with them. It was really amazing,” he said.

Coldplay announced the collaboration on SNS. Fans can pre-save the song on all digital music platforms. A physical CD single—complete with lyrics in the handwriting of both groups—was also available for pre-order, but it sold out fairly quickly. It was printed on sustainably sourced board, and it also had a spot UV gloss varnish on the front and back cover.

Furthermore, for every cassette tape, CD, and vinyl album purchased on the Coldplay store, the British band will plant and sustain one tree with One Tree Planted, an environmental non-profit organization 501(c)3 that plants trees in countries around the world.

“My Universe” is the second single from Music of the Spheres. The first single, “Higher Power,” was released in May and peaked at No. 12 in the UK. Meanwhile, the album’s final track, “Coloratura,” was released as a promotional single in July.

Fans of both groups are preparing for a massive fan-led promotional blitz for the song. If “My Universe” debuts atop the US Billboard Hot 100, it will be BTS’s sixth No. 1 hit. Meanwhile, a No. 1 debut for this song would give Coldplay its second. They earned their first and last Hot 100 leader in 2008 when they dropped “Viva La Vida.”

If everything works out in their favor, “My Universe” could be really big for BTS and Coldplay.