There are happy songs -- and then there is Happy." The bouncy tune by singer/composer/producer/rapper Pharrell Williams has occupied the No. 1 spot on the charts for more than a month. It's spurred countless covers -- including one by Academy Award-winning actress Gwyneth Paltrow, reprising her guest star role in the 100th episode of "Glee." There is even a YouTube version of "Happy" that has gone completely to the dogs. It has managed to seemingly capture the rush of happiness in its lyrics and melody. Not a bad trick for a tune that slowly grew from a single on last summer's "Despicable Me 2" soundtrack to such popularity that Robert Morast, a writer for the Virginian-Pilot, recently entered into a debate of whether it should be considered for the official state song of Virginia. "Pharrell's hit track is a jolt of mood-lifting music," wrote Morast. "And while it's fine to be happy, the best art is crafted with a range of emotional perspectives." Even with its slow build, "Happy" caught ears from the beginning. Upon release it was quickly dubbed "an instant contender for 2013's Song of the Summer" by Rolling Stone. Since then, it's topped the charts in more than a dozen countries besides the United States, including the United Kingdom, France, Germany and Poland. Williams has partnered with the United Nations Foundation in celebration of Thursday's International Day of Happiness, encouraging fans to donate to the organization and submit content to his 24Hoursof Happiness.com site.