MARC21       006c'07-12  Accompanying matter
     Values: 
              #   No accompanying matter
              a   Discography
              b   Bibliography
              c   Thematic index
              d   Libretto or text
              e   Biography of composer or author
              f   Biography of performer or history of ensemble
              g   Technical and/or historical information on instruments
              h   Technical information on music
              i   Historical information
              k   Ethnological information
              r   Instructional materials
              s   Music
              z   Other