Rascal Flatts' smooth vocal harmonies, arena rock-style production, and pure pop-meets-twang sound made them one of the most successful country acts of all time. The group's sixth studio album, UNSTOPPABLE, was aptly titled, as the disc's first single, "Here Comes Goodbye," set a first week sales record upon it's release. A melancholy but ultimately inspirational tale of family tragedy, the song, as well as the album's second single, "Forever," showed a more serious side of Rascal Flatts.