Martin Garrix gave fans a surprise during his Tomorrowland set.

The Dutch DJ debuted his new collaboration with U2, “Fireflies,” during his headlining performance Friday (July 17) at the festival in Boom, Belgium.

For the debut, U2 guitarist The Edge joined Garrix onstage to perform the previously unheard track, while Bono‘s vocals played as part of the song.

Garrix closed out Tomorrowland’s opening day with the main stage headline set at De Schorre.

For the final song of the night, The Edge added his signature guitar work to “Fireflies,” marking the song’s live debut before its official release.

“Fireflies with @u2 out soon.. premiered at @tomorrowland,” Garrix wrote on Instagram alongside a clip of the performance.

The upcoming single is now available to pre-save on Spotify and Apple Music.

Garrix and U2 are no strangers to collaborating. They previously joined forces on “We Are the People,” the official song of the UEFA Euro 2020 tournament, which reached No. 12 on Billboard‘s Hot Dance/Electronic Songs chart in May 2021.

Garrix also produced U2’s “Your Song Saved My Life” for the Sing 2 soundtrack, while Bono co-wrote several Garrix songs, including “Angels for Each Other,” “Catherina” and “Weightless.”

It was unclear at press time whether “Fireflies” will appear on an upcoming studio albums from Garrix or U2.

U2 recently released “Street of Dreams,” the soaring lead single from the band’s as-yet-untitled next studio album, its first since 2017’s Songs of Experience. Due later this year, the album features “Street of Dreams,” produced by frequent collaborator Jacknife Lee.

It arrives after U2 released the surprise six-song Easter Lily EP in April, just two months after the band’s Days of Ash EP was released in February.

Check out Garrix’s Instagram post below.