But the inspiration for the rock tune has little to do with a failed romance. Instead, it comes from one of the worst tragedies in recent memory - the genocide in Rwanda nearly two decades ago.
Lead singer and writer Isaac Slade was visiting the Rwandan capital of Kigali last year when he found himself standing on the site where more than 250,000 victims of the country's 1994 genocide were buried. Then he had an epiphany.
"(I was) at this gathering with a bunch of local (people) and ex-pats, all standing in circle holding hands, just kind of thinking and talking about Rwanda. This chick was standing next to me and I couldn't tell if it was her heartbeat or mine, but it felt like the country was getting its pulse back to it," Slade remembered.
"I busted out my phone and wrote that pre-chorus of this song called 'Heartbeat,' and wrote some of the chorus on the way back," he said.
The vocalist also spent time with President Paul Kagame after a friend arranged a meeting. The visit took place near Kagame's birthday, so Slade performed a solo version of The Fray's biggest hit so far, "How to Save A Life," in the presidential place. Slade bonded with Kagame and the two men spoke of family and the darkest period in Rwandan history, when extremist Hutus killed more than 500,000 Tutsis and moderate Hutus in the country. Kagame led Rwandan Tutsi soldiers at the time, and has been credited with ending the genocide.
After Slade talked to Kagame, he said he understood the purpose of "Heartbeat."
"One of the few sayings that the Jewish faith and the Muslim faith share (is) that if you kill one man, you're guilty of killing all of us," Slade said. "So I wanted to flip that to the opposite. If you serve one man, if you do step off your pedestal or whatever like Kagame did and risk his life and led those people out of exodus, you're essentially loving the entire world."
The song is on the band's third album, "Scars & Stories," which was released earlier this month. Producer Brendan O'Brien, known for his work with Pearl Jam, Bruce Springsteen and Rage Against the Machine, certainly helped shape the song and the rest of the album, said Joe King, the band's guitarist and co-vocalist.
"He pinned us on both sides, and that's what we needed," King said.
Slade added: "Every album, so far, has been a snapshot of who we are and where we are. Here we are."
Both Slade and King feel the experiences that led up this album left them more mature.
But then Slade added: "We're mature, but certainly not that mature."