Chris Martin's pop worry
Chris Martin worried the rest of Coldplay would think his new songs were "too pop".
The 38-year-old frontman brought in Mikkel Storleer Eriksen and Tor Erik Hermansen aka production duo Stargate - who have previously worked with Rihanna, Katy Perry and Lady Gaga - for new record 'A Head Full of Dreams' and was unsure what his bandmates would think of the test sessions.
He said: "I was nervous about Guy [Berryman] and Will [Champion] saying this is too pop. But they got along so well with Tor and Mikkel. It's marrying these two worlds, often in two different rooms."
The album is their seventh and Chris believes it makes the end of the first chapter of their career.
He said: "If you think about the journey of Leo Messi from playing in the playground to putting his boots on before the Champions League final, that's where we are."
Coldplay's last album, the introspective 'Ghost Stories', was released just two months after Chris and wife Gwyneth Paltrow announced their separation and his bandmates felt very "protective" of him.
Guitarist Jonny Buckland told Q magazine: "There were times when we felt very protective of Chris."
Will added: "He put a lot of himself into those songs. I don't envy him being the frontman."