NOBODY was shocked more than American hit songwriter and pop star Bebe Rexha when she blasted to the top of the charts worldwide with a country tune.

Teaming with bro-country duo Florida Georgia Line, the cross-genre hit Meant To Be peaked at No. 2 on the ARIA charts and has amassed half a billion streams.

“I knew it would be a special song in the US but I never thought it would go overseas because I thought it’s country music,” she said.

“It is shocking to me and kind of confusing to me too. For a long time, I didn’t feel like it was my record because it wasn’t like my sound.

“I think people consider it country because there’s a country act on there but if you were to listen to the song, it’s just guitar and piano and that is timeless, classic like a little black dress.”

Rexha has been at the vanguard of the new breed of pop hitmakers for the past five years, since grabbing the world’s attention with her songwriting chops on Eminem and Rihanna’s Grammy winning song The Monster.

That success coincided with the launch of her own pop career, commanding the charts with a raft of genre-busting hits from Me, Myself & I with rapper G-Eazy, In The Name Of Love with dance producer Martin Garrix and Back To You with One Direction’s Louis Tomlinson.

In Australia to launch her latest single I’m A Mess and debut album Expectations, Rexha revealed an unlikely setting for her songwriting.

“A lot of those lyrics I wrote in the bathtub. I run the water and talk to myself and record it as a voice memo,” she said.

“Those lyrics come from real things I think about constantly.”

I’m A Mess may sound like she’s crying over a guy who doesn’t like her back but it also allowed her to share her battles with anxiety and depression.

“My mum absolutely hates that song. She said ‘Look at Meant To Be, couldn’t you put out another song that’s happy and positive’,” Rexha said, laughing.

“But I’m A Mess is a real side of me, something I deal with every day, with anxiety and depression.

“It’s about love too … That song was inspired by a guy I really still like, it’s been a year now, but I don’t think he knows the song is about him.”

While Rexha is delightfully unfiltered in an era of scripted pop stars, the recent controversy which erupted over Girls, her collaboration with Rita Ora, Cardi B and Charli XCX, because of its lyrics about same-sex attraction made her wary of the social media swamp.

“In general, a lot of the things I do now have to very thought out, especially a situation like that,” she said.

“You do what’s true to you, what you believe in and you love but you can’t ever please everybody. That’s why you gotta stay off the internet.

“I was at dinner when I was on tour with Katy Perry and went on my Twitter and was reading the comments and got really bummed about what somebody had said.

“She was like ‘Why are you reading the comments? That’s the No. 1 rule, don’t read the comments.’

“Because you will see someone telling you you’re fat and ugly and you should die and you’ll think ‘Oh my God, is that true?”

Rexha hopes to return to Australia to play concerts next year.