'No one will confuse this with any of our other records', Sara says. 'It's got a bigger, bolder, happier sound'. Tegan is explicit about the supersized ambitions motivating the record. 'I kept asking myself: Can I hear this in an arena? Can I hear this on a teenager's iPod as they're riding the bus to school?' Heartthrob doesn't just sound different, it represents a more collaborative way of making music. For the first time, the sisters actually wrote a lot of the songs together (in the past there were Tegan songs and Sara songs), and they surrendered more control than usual in the studio, dividing songs between 3 producers (Greg Kurstin, Justin Meldal-Johnsen, and Mike Elizondo) and a handful of outside musicians to capture the sound they were looking for. Tegan and Sara are both effusive about Kurstin's role in the process.