Up-and-coming artists like Big K.R.I.T. and the rap collective Odd Future are using DIY ethos and internet savvy to bring hip hop’s underground to the mainstream. Today: A discussion about the changing face of hip hop. Plus: Our Pick Three series continues with one critic's three recent favorite releases. And: A live performance from The Ensemble Hilka, a chorus that joins us to sing the lost songs of the so-called Chernobyl Zone.