Record any audio, with Audio Hijack 3
It's been a long time coming, but today Rogue Amoeba introduces Audio Hijack 3. It's immediately available for Mac OS X 10.9 and up, and it's a huge upgrade.
Audio Hijack is a powerful utility for recording any audio on Mac OS X. Audio from individual applications like Safari or Skype, hardware audio devices like microphones and mixers, and even the entire system audio output, can all be saved. Simply put, if it can be heard on Mac OS X, Audio Hijack can record it.
See the video of it here.