Amusia

Amusia is the loss or reduction of musical abilities as a result of brain damage or biological genetic factors. Sufferers have a difficulty or inability to perceive music and its components (like notes or melodies). They have an "inability" or difficulty singing and recalling simple songs like "Happy Birthday". Many sufferers still enjoy music because they can still perceive the emotional aspects of it - for example whether the music is happy or sad and what the lyrics say.