registered models to About's admin.py

joei_yucoco_music/About/admin.py

 from django.contrib import admin
 
+from .models import Artist, Album, Song
+
+class ArtistAdmin(admin.ModelAdmin):
+    model = Artist
+
+class AlbumAdmin(admin.ModelAdmin):
+    model = Album
+
+class SongAdmin(admin.ModelAdmin):
+    model = Song
+
+# registering the model and the admin is what tells
+# Django that admin pages must be generated for the models specified
+admin.site.register(Artist, ArtistAdmin)
+admin.site.register(Album, AlbumAdmin)
+admin.site.register(Song, SongAdmin)
+
 # Register your models here.