You need to change TEMPLATE_CONTEXT_PROCESSORS:
- add the default context processors from django
- add
django.core.context_processors.request - add
mpdsongvote.context_processors.mpdsongvote
To update the playlist even when nobody is voting, you need to run via cron:
DJANGO_SETTINGS_MODULE="yourproject.settings" python update_playlist.py. The interval should be smaller than the playtime of two songs.