Example:
Aerosmith
+Beach Boys
-Apparel
-Novelties
-Tour Memorabilia
-other
-Posters
+Beatles
-Apparel
-Novelties
-Tour Memorabilia
-other
-Posters
Doors
Duran Duran
+Pink Floyd
-Apparel
-Novelties
-Tour Memorabilia
-other
-Posters
+Presley, Elvis
-Apparel
-Novelties
-Tour Memorabilia
-other
-Posters
Radiohead