The United Nations is marking International Day of Happiness by creating "the world's happiest playlist".
Stars including Ed Sheeran, David Guetta, John Legend and James Blunt have contributed to the playlist, as have United Nations Messengers of Peace and Goodwill Ambassadors.
UN Secretary General Ban Ki-moon nominated Signed Sealed Delivered by Stevie Wonder, who is himself a UN Messenger of Peace, advocating on behalf of persons with disabilities worldwide.
Mr Ban said: "The United Nations is happy to be partnering with MixRadio to raise awareness of the International Day of Happiness.
"On this day we are using the universal language of music to show solidarity with the millions of people around the world suffering from poverty, human rights abuses, humanitarian crises and the effects of environmental degradation and climate change."
The campaign is being fronted by singer/songwriter Cody Simpson, and m usic fans are being encouraged to tweet the song that makes them happiest with the hashtag #HappySoundsLike.
On March 20, Simpson will choose five submissions to be included within the official playlist.
Simpson said: "I am really pleased to be part of such an amazing campaign to raise awareness of International Day of Happiness.
"I hope everyone gets behind the day and shares the track that makes them happiest.
"I will be choosing five tracks the general public suggest to be part of the official playlist, #HappySoundsLike, launching on Friday March 20 for you to all listen to."
The International Day of Happiness was established by the UN General Assembly in 2012 to promote the idea that "the pursuit of happiness is a fundamental human goal". In its 70th anniversary year, the UN will be undertaking several campaigns to help achieve this goal.