One Direction's Midnight Memories: Go Inside Their Late-Night Recording Sessions.

'MIDNIGHT MEMORIES'
The song borrows from real-life details of the guys traveling the globe, piling into Addison Lees and hitting house parties with stellar kitchens. He says it "definitely personifies their lifestyle."

"It's the title of the album and it just happens to fall in line with Up All Night, Take Me Home, it's all references to in the evening," Bunetta said. "And midnight memories are where most of the memories of this record were made. [It] was between midnight and 5 in the morning. We have so many memories of just being in the studio or being after a show or being in the back of the bus or going to one of the guys' places and hanging and writing. Or, [it's also] just when you're young and that's when you kind of have all your experiences."

'STRONG'
Louis Tomlinson and Grafitti6's Jamie Scott co-wrote this track together, putting the singer's sensitive side on full display.

"We got into this discussion about how when you tell someone like 'I need you, I love you and I need you 'cause you make me strong,' essentially you can scare someone off. It's pressure, so people just kind of run from it. So, that's what the lyric is," recalled Bunetta, who also helped produce songs on the album. "It's saying 'I'm sorry if I say this, but f--- it. And obviously Louis' been in a relationship [with Eleanor Calder] for a long time. It was just sort of a thing that I think all guys feel, having to uphold a man 'I'm strong' [philosophy], and kind of throwing that idea out the window."

'DIANA'
The Justin Bieber-approved track leaked back in September and fans named Diana immediately gushed. So, is there a Diana-type figure that actually inspired the upbeat song?

"Can't tell! It's definitely about somebody, maybe one day somebody will tell," Bunetta teased. "But we can't tell."

He then broke down why he thinks the song has resonated with fans, aside from its title.

"I think that the lyric probably pertains to what a lot of the fans are going through and feel... People feel like they're alone and that's what their escape is, Twitter and [finding] people that also relate to them, and everyone finding each other from different parts of the world that are going through the same things," he said. "[I think] it was a kind of a pretty accurate depiction of the loneliness someone can feel in such a huge world and someone saying 'Hey, I feel you. I know you're there. I notice you; it's OK. You're not alone'."

'BETTER THAN WORDS'
This track came partially from the mind of Liam Payne while the team was lying on the floor in a hotel hallway playing with his dog and beatboxing.

"We ran into the hotel room, where the studio was set up. We laid it down and as I was making the quick little beat Liam went [to the bathroom] and he came out and he was like 'Bro, what if we write a song using all song titles?' And I don't know who it was [but] 'better than words' popped out somehow," he recalled.

"And then were like, 'Sh--, we got it. What if you're saying that you can't even describe how good someone's love is because it's better than words. So you can't even use your own words. You have to use other people's words [from songs] and even those words aren't good enough.' I love that song."