When you study music on high school, college or music conservatory, you
usually have to do ear training. Some of the exercises, like sight singing
is easy to do alone. But often you have to be at least two people, one
making questions, the other answering.

GNU Solfege tries to help out with this. Solfege is a computer program written
to help you practise the more simple and mechanical exercises on your own.
These are the exercises written so far:
   * Recognise melodic and harmonic intervals
   * Compare interval sizes
   * Sing the intervals the computer asks for
   * Identify chords
   * Sing chords
   * Scales
   * Dictation
   * Remembering rhythmic patterns

WWW: http://www.solfege.org/