As part of the International Day of Happiness (March 20), the United Nations is on a mission to create the happiest playlist ever, and they've asked some of today's most popular musicians for help. Ed Sheeran, John Legend, Cody Simpson, James Blunt and David Guetta are all signed on to help finalize the playlist.

If you're wondering why "Happy" singer Pharrell isn't on there, don't think he was left out on purpose. His song was part of last year's "24 Hours of Happiness" campaign.

Anyone can submit song ideas for the playlist using the hashtag #HappySoundsLike and the songs don't have to be new; they can be oldies but goodies like Bobby McFerrin's "Don't Worry Be Happy," --- whatever it is that makes you smile.

The final playlist will be curated at the end of the week, so get tweeting!

Follow Emily on Twitter: @EmLaurence