A bunch of big cable TV companies have teamed up to give you a present: Free Wi-Fi. If you're a customer of Comcast, Time Warner, Cox, Cablevision or Bright House, you'll be able to use Wi-Fi hotspots from any of those companies. Fifty thousand hotspots nationwide will show up under the name Cable Wi-Fi. So what's in it for the cable companies? Plus, the most musical cities in America.