(subclass MusicChart List) | Music.kif 1119-1119 | Music charts is a subclass of list |
(subclass SinglesChart MusicChart) | Music.kif 1132-1132 | Singles chart is a subclass of music charts |
(subclass AlbumChart MusicChart) | Music.kif 1144-1144 | Album chart is a subclass of music charts |