Beyoncé: All About That Bass

Before Meghan Trainor was a household name, she operated strictly behind the scenes as a Nashville-based songwriter. When she co-wrote the retro-pop anthem All About That Bass, she deliberately shopped it around to major artists, with her publishing camp floating the track directly to Beyoncé's team. Believing she didn't have the "pop star look" herself, Trainor was stunned when multiple artists - including icons like Adele - passed, leaving her to record the Diamond-certified track herself.