We as a society owe Kesha Sebert an apology. When she burst onto the scene in 2010 with the megahit "Tik Tok" she was dismissed as a Gaga wannabe, a pop flash in the pan. Since then, of course, Kesha has dropped the both the "$" and the pretense. She's a genuine songwriter who has had to struggle with some serious shit. Rainbow is at last her signature document, a work that shows her range, her willingness to experiment, and most of all, her strength.