DJ Martin Garrix debuted a new collaboration with U2, titled "Fireflies," during his Tomorrowland set on Friday in Antwerp, Belgium, with the Edge joining him on stage. The performance featured the Edge's guitar work layered over prerecorded vocals from Bono, and Garrix confirmed on social media that the track will be released soon, sharing a pre-save link for fans.

The pairing extends a decade-long creative relationship between Garrix and the Irish band, which has previously produced the UEFA 2020 anthem "We Are the People" and the Sing 2 soundtrack track "Your Song Saved My Life," with Bono also co-writing several Garrix singles. It remains unclear whether "Fireflies" is a standalone release or connected to U2's forthcoming studio album, their first collection of new material since 2017's Songs of Experience, timed to mark the band's 50th anniversary and following last week's single "Street of Dreams."