There's an audio program called "Audio Recorder" for Ubuntu (and Linux Mint) that lets you record whatever sound or audio stream is being played through your sound card. It's super simple and easy to use and it will let you record internet radio stations, podcasts, Youtube videos, or whatever else you want to record.

Just follow the following steps and you can have Audio Recorder installed on your Ubuntu or Mint system:

  1. Add the Audio Recorder software repository by running sudo apt-add-repository ppa:osmoma/audio-recorder
  2. Now update your package list with sudo apt-get update
  3. Finally, install Audio Recorder by running sudo apt-get install audio-recorder

Now you should be able to find the Audio Recorder program in your programs menu.