In support of the 25th anniversary of UNICEF’s Convention on the Rights of the Child, a bunch of musicians and celebrities from all over the world have come together to help create the world’s largest charity sing-along with a version of John Lennon’s classic song, “Imagine.” The video features stars like Katy Perry, Adam Lambert, Will.i.am, David Guetta, Nicole Scherzinger, Danny O’Donaghue from The Script, Lance Bass, MAGIC! frontman Nasri and Lennon himself. The project gives you the opportunity to get in on the act by downloading a special app, on which to record your own version of “Imagine,”. You can also send personal messages on your idea of a better world for children. Then, share the recording with the hashtags #EVERYVOICECOUNTS and #IMAGINE. Your own version of the song could then be used by David Guetta to produce a multi-lingual “world” version of “Imagine” to be released New Year’s Eve.Visit Imagine.Unicef.org for more information. Non-musical stars who are featured in the video include Courteney Cox, David Arquette, Idris Elba, Scott Foley, Seth Green, Taye Diggs, Patricia Arquette, Dianna Agron, Nina Dobrev and Amy Brenneman, among others.