New York - U2 rocked out on a guitar-charging first track of its upcoming album, which the Irish rock legends had largely finished last year but revisited following Donald Trump's shock election victory.
In the first taste of its upcoming album Songs of Experience, the band released The Blackout, a rock number with echoes of early-1990s Achtung Baby era U2 with a dominant bass line pushing The Edge's heavily distorted guitar.
U2 released the song through a "video" of a live performance - which, true to the song's title, is a black screen - on Facebook. U2 earlier hinted at the song by sending fan club members anonymous letters in the mail of silhouetted figures, which arrived when the United States was experiencing a historic solar eclipse on 21 August.
Listen to The Blackout here:
The track, however, will not be considered the lead single from the album. That will be You're the Best Thing About Me, which U2 said in social media posts would come out on 6 September along with more details on the album.
Songs of Experience - its title a reference to a collection of poems by William Blake - is a sequel to 2014's Songs of Innocence, which reflected heavily on frontman Bono's childhood in suburban Dublin.
The latest album is set for a more conventional release after U2 acknowledged its strategy backfired for Songs of Innocence.
Apple, as part of a product promotion, transmitted the album for free last year to the world's half-billion iTunes accounts - whether users wanted to hear U2 or not.
A new outlook after Trump
The band, known for its human rights advocacy, said it completed most of Songs of Experience last year but decided to return to work after Trump stunned the world by winning the White House.
"Most of it was written in the early part of 2016, and now, as I think you'd agree, the world is a different place," The Edge told Rolling Stone earlier this year.
In a more recent interview with Apple's Beats 1 radio, Bono voiced dismay at Trump's push to build a wall on the border with Mexico, noting that even fellow Republican president Ronald Reagan embraced immigration.
Bono said that the new album had a number of songs conceived as letters - including one, American Soul, addressed to the United States and pointing to the country's historic welcome of foreigners.
"We have all got a stake in the American idea. We want it to succeed," Bono said.
"It's a beautiful idea and that's why we get worked up about it," said Bono, whose best-known songs include Pride (In the Name of Love) about slain civil rights icon Martin Luther King Jr.
Bono has said that U2 also needed time to cut down on the size of Songs of Experience and wanted to return to the studio to fine-tune the music.
U2 is releasing the new songs as the band tours North America to mark the 30th anniversary of The Joshua Tree, generally considered its definitive album.
The Joshua Tree reached into the roots of both Irish and American music as Bono took aim at US support for Latin American dictatorships under Reagan.