Madonna Claims Lady Gaga Refused To Perform With HerThe Material Girl claims there are no hard feelings over the brush off, but her onstage rant seems to say otherwise.
Madonna To Mash Up "Express Yourself," Gaga's "Born This Way" On Tour
Jim & Kim's Jammin' With Gram (Madonna Edition): Express Yourself!
Madonna's Best Live Television Performances
Is Lady Gaga's "Born This Way" Better As A Ballad?