"When I hear [people write off pop music], it almost hurts me because I think what's so beautiful and so amazing about pop music is that it's so, so complicated," she says. "And to make music sound so easy takes tremendous talent and a lot of skill.
"There's a snobbiness [against] that kind of music. I was probably guilty of feeling that way in the past. But once I started trying to make that kind of music, I realised how complicated it was."
Sara and her twin sister Tegan have been making music since they were 15 yeas old. They taught themselves how to write songs and released their debut album independently in 1999. They caught the attention of Elliot Roberts, the manager of iconic Canadian singer Neil Young, who quickly signed the girls to his label. Their indie rock sounds and creative songwriting led to a huge following as they played at every big music festival from Coachella to Glastonbury, and released five more studio albums.
But after making music for basically half their lives, Tegan and Sara needed a new challenge for their seventh album.
"It would be easy for us to go [and] make really random, weird arty music and not have many people like it," says Sara. "I'm not saying that there isn't value to that music but what seems really challenging and difficult at this point of our career is trying to become more popular and accessible, and trying to write music that appeals to a lot of different kinds of people."
So they turned to pop music.
"We discussed making something sonically bigger and maybe more pop-ready and friendly, like something that would not be a weird fit on radio or television," she says. The biggest hurdle was "to continue to have integrity and the artistic freedom that we always had, but to force ourselves to make something that would garner us a new audience and fan base, while continuing to honour the fan base we already have.
"So it was complicated, one of the more complicated records [we've] made. It challenged us as artists. My biggest fear was that we would go in to the studio and make something that people expected. Even if it meant losing fans, I really wanted to make something that challenged us."
But the fans stayed: Heartthrob, which was released earlier this year, became their highest charting album on the Billboard Top 200, debuting at number three. Lead single Closer garnered praise from both critics and singers such as Katy Perry and Kylie Minogue.
They may As they take their career in a new direction, Tegan and Sara can always depend on one another. Says Sara: "Although I really enjoy the solitary privacy of writing music alone, when it comes to the actual recording and performing, I really enjoy the comfort and safety of having Tegan there to accompany me - and I think that works the same for her."