PLEASE!!!! DOES ANYONE KNOW THE NAME OF THE FIRST SONG THAT CHRIS MARTIN SANG AT THE GRAMMY'S TONIGHT?

Chris Martin only sang a little bit of the song. Jay z came in the middle and sang a verse, does anyone know the name of the song? it sounds so familiar but i can't seem to find it! please if anyone knows the name of ot can u please tell me! Thanks:)