section_path: Art and entertainment/Oral and aural tradition
section_name: Oral and aural tradition
paragraph_text: Oral and aural tradition
  
  Many types of music, such as traditional blues and folk music were not written down in sheet music; instead, they were originally preserved in the memory of performers, and the songs were handed down orally, from one musician or singer to another, or aurally, in which a performer learns a song " by ear ". When the composer of a song or piece is no longer known, this music is often classified as "traditional" or as a "folk song". Different musical traditions have different attitudes towards how and where to make changes to the original source material, from quite strict, to those that demand improvisation or modification to the music. A culture's history and stories may also be passed on by ear through song.