Twitter, which released its music application to a handful of celebrities last week, today announced on "Good Morning America" that the rest of the world can now pile in. The free application, built using technology from We Are Hunted, lets users discover music through artists' and others' Tweets, listen to their music using Rdio or Spotify, check out their concert dates, watch their videos on YouTube or Vevo and buy songs via iTunes. The service is available at https://music.twitter.com and as a separate app for the iPhone through the App Store.