"Bad Day" — Daniel Powter

Canadian singer-songwriter Daniel Powter recorded "Bad Day" with producer Jeff Dawson back in 2002 and couldn't get a label to release it — after a failed New York audition, he went home to Vancouver assuming the door was closed. The song found its own way out: Warner Bros. Records chairman Tom Whalley heard a demo and signed Powter in 2003, a French Coca-Cola television ad at Christmas 2004 put the song in front of millions before it was even released, and in early 2005 "Bad Day" went to French radio. It became the most played song on European radio in 2005 and peaked at number two in the UK.

America got it a year late and made it even bigger. The fifth season of American Idol used "Bad Day" to score the montage of every eliminated contestant, and the media credited that weekly send-off as a major factor in the song's US success. It hit number one on the Billboard Hot 100 in the spring of 2006, spent 19 weeks atop the Adult Contemporary chart, and in December 2006 became the first song ever to sell two million digital copies in the United States. Billboard ranked it the number-one song of 2006 outright, and it earned a Grammy nomination for Best Male Pop Vocal Performance. The Marc Webb-directed video — two downcast strangers sharing a routine until they finally meet — has racked up roughly 293 million views since its official YouTube release.

Powter never came close again: Billboard later dubbed him the top one-hit wonder of the 2000s, with "Bad Day" standing as his only Hot 100 hit. The song's ubiquity made it a punchline in its own time — Saturday Night Live parodied it, and "Weird Al" Yankovic wanted to record "You Had a Bad Date" before Powter's initial refusal sent him off to make "White & Nerdy" instead. Even the Chipmunks covered it. For one long year, everyone's bad day had the same soundtrack.