Syracuse.com | Katy Perry, Taye Diggs, more celebs 'Imagine' the world's largest singalong for ... Syracuse.com Katy Perry and Taye Diggs are among the celebrities lending their voices to UNICEF's #Imagine project. (Video still). Print · Geoff Herbert | gherbert@syracuse.com By Geoff Herbert | gherbert@syracuse.com The Post-Standard Email the author | Follow on ... Priyanka Chopra, Sunidhi Chauhan Sing John Lennon's Imagine With Katy ... 'Imagine' app launched Katy Perry and will.i.am to cover Imagine for UNICEF |