For years, the genre known as "black metal" has lived on the outskirts of music’s underground. But that might not be the case for much longer. Today: How new bands on the scene have left the genre's notorious violence behind – and won over many mainstream listeners. Plus: Irish rock band Bell X1 takes its name from the world's first supersonic aircraft. They'll generate their own sonic waves in the studio when they perform live. And, we hear about Coldplay's new concept album.