Beyonce Baby Tweets: Rihanna, OneRepublic + More Congratulate Beyonce and Jay Z on the Birth of Blue Ivy

In the words of OneRepublic, "musical royalty has just been born." Beyonce and Jay-Z welcomed their first child, a girl named Blue Ivy Carter, late Saturday night. As expected, Sunday was baby day around the world as music fans, the media and more reached out to share their congratulations, welcome the new arrival and even shed their two cents on her less-than-traditional name. Of course, those close to Bey and Jay -- their artist peers -- wanted to join the celebration as well. See what Rihanna, OneRepublic, Diddy, Beyonce's sister Solange and more had to say about the arrival of sweet Blue Ivy Carter!