When Glen Hansard and Markéta Irglová collaborated to write the songs for the 2006 film Once, they didn't realize their partnership was going to earn them an Academy Award for Best Original Song for "Falling Slowly." They also starred in the Dublin-set film, playing a busker and an immigrant who write songs together. Their oncreen romance became reality as they spent two years together during a grueling world tour that eventually caused more and more tension in their relationship.