old_contents: from django.contrib import admin
  from .models import Artist, Event, Venue
  
  
  admin.site.register(Artist)
  admin.site.register(Event)
  admin.site.register(Venue)
  
new_contents: from django.contrib import admin
  from .models import Artist, Event, Venue
  
  
  class ArtistEventsInline(admin.TabularInline):
      model = Artist.events.through
      verbose_name_plural = 'Events'
      extra = 1
  
  
  class EventArtistsInline(admin.TabularInline):
      model = Event.artists.through
      verbose_name_plural = 'Artists'
      extra = 1
  
  
  class EventInline(admin.StackedInline):
      model = Event
      extra = 1
  
  
  class ArtistAdmin(admin.ModelAdmin):
      fieldsets = [
          ('Name', {'fields': ['name']}),
      ]
      inlines = [ArtistEventsInline]
      search_fields = ['name']
  
  
  class EventAdmin(admin.ModelAdmin):
      inlines = [EventArtistsInline]
      list_display  = ['title', 'datetime', 'venue']
      list_filter   = ['title', 'datetime', 'venue__name']
      search_fields = ['title', 'datetime', 'venue__name']
  
  
  class VenueAdmin(admin.ModelAdmin):
      inlines = [EventInline]
      list_display  = ['name', 'city', 'country']
      list_filter   = ['name', 'city', 'country']
      search_fields = ['name', 'city', 'country']
  
  
  admin.site.register(Artist, ArtistAdmin)
  admin.site.register(Event, EventAdmin)
  admin.site.register(Venue, VenueAdmin)
  
subject: Customize Artist, Event, Venue admin forms