It has already been reported on MOG that Fergie will perform at the Grammy awards ceremony this Sunday and that she will sing with RnB star John Legend. But according to inside sources who have been attending the rehearsals, it looks like Fergie will also be performing a duet with Slash:News and photo via BlenderAlso from Blender, here is footage from the Black Eyed Peas' benefit/Grammy show last night:Fergie:Will. & Lil Jon: