Coldplay come out of darkness with 'hippie' album

London- British stadium rockers Coldplay will on Friday release their seventh album "A Head Full of Dreams", which heralds a return to their indie roots and A-List collaborations, including this time with US President Barack Obama.

The four-piece band have already given fans a sneak preview of all 11 tracks on the album, which singer Chris Martin has hinted may be their last, and its debut single "Adventure of a Lifetime" came out last month, hitting number 14 in the British charts.

Its upbeat tempo and disco groove suggested a departure from last year's subdued album "Ghost Stories".

Other tracks mark a return to the jangly guitars, soaring vocals, wordless choruses and epic ballads that earned the band a worldwide following, but there are also occasional forays into hip-hop and spoken word.

Martin has described it as "a hippie album" that fuses "all the music that we love, from Drake to Oasis".

Oasis singer/songwriter Noel Gallagher is one of the high-profile guests on the album, alongside Beyonce and Swedish artist Tove Lo.

There is also an emotional contribution from Martin's former wife Gwyneth Paltrow exploring the pair's high-profile divorce - a theme that underpins the record.

"So how come things move on? How come cars don't slow? When it feels like the end of the world, When I should but I can't let you go," read the lyrics for "Everglow", which were written by Paltrow who also provided backing vocals.

"Kaleidoscope" even features a sample of President Obama singing "Amazing Grace" during his eulogy for the pastor Clementa Pinckney, who was killed with eight others during July's church shooting in Charleston, South Carolina.

The band on Monday premiered "Hymn for the Weekend", Martin's feelgood duet with R&B superstar Beyonce that is set to soundtrack dancefloors around the world.

"It started as a different kind of vibe, Chris wanted to write a party song," bassist Guy Berryman told BBC Radio 1.

"She (Beyonce) was in and out in five minutes," he said of the studio session.

The early reviews were largely positive, with the New York Times calling it "blissful and bittersweet." "After darkness, light: Coldplay has wallowed and Coldplay has wept, but there comes a season for renewal," wrote reviewer Nate Chinen.

Singer Martin previously described the record as "the completion of something", sparking rumours it could be their last.

The band will tour the new album next year, with 26 stadium shows confirmed across 14 countries in Europe and Latin America.

These will include three nights at London's Wembley Stadium, one night at Rio's Maracana and a show at Berlin's Olympiastadion.

The album is produced by the team behind Katy Perry's "Firework" and Beyonce's "Irreplaceable".

Eagle-eyed fans were alerted to the possibility of a new album last month, when a pattern that Martin had worn on a T-shirt at an event in Global Citizen Festival in New York in September appeared on social media.

The interlacing rainbow-coloured rings on a black background, which will appear on the album cover, had appeared on a poster in the British capital's underground train network with text reading only "December 4".

The band - responsible for hits such as "Yellow", "Viva la Vida" and "Clocks" - also released two animations of the colourful pattern on its official Twitter and Facebook pages.

In all the band has sold over 100 million albums worldwide and won numerous accolades, including seven Grammy Awards, multiple MTV awards and eight Brit Awards.