Sorry, Clay Aiken and Ruben Studdard. But your summer tour just took a significant backseat. Rihanna has confirmed that she’ll take her new album, “Rated R,” on the road this summer, leading a “Last Girl On Earth” North American tour that will also include another diva burning up the charts: Ke$ha! Which of these singers would you be more excited to see live? The women, along with rapper Nicki Minaj, will start the proceedings in Seattle on July 2, make 25 stops altogether, and conclude on August 25 in Chicago. Tickets go on sale at LiveNation.com on April 9. Check out the complete schedule of dates and locations below… Friday, July 2 –
