Need help with this basic query (annotate vs aggregate)

Here is my model:

class PlaylistTag(models.Model):
playlist = models.ForeignKey(Playlist)
tag = models.CharField(max_length=128)
tag_count = models.PositiveIntegerField(default=1)

The way this model works is simple. If you add a tag to a playlist,
and the tag doesn't exist, the tag_count is 1. If you add the same tag
again to that playlist, the tag_count is incremented. If you remove
that tag, it is decremented. If it reaches 0, I remove the row
entirely.

A playlist can have multiple tags and a tag can belong to different
playlists.

What I want to do is wildcard search for a tag sorted by tag count
descending, but instead of returning duplicate playlists, I want to
sum the tag_count for each playlist that the search returns.

For example:

Playlist 1, "foo", 3
Playlist 1, "foobar", 2

A query for "foo" would return both of those rows, but I want to sum
them for that playlist so that playlist has a "score" of 5 for that
query and only return that playlist once in the querySet.

querySet = PlaylistTag.objects.select_related().filter(tag__icontains
= query).annotate(score=Sum("tag_count")).order_by("-score")

The missing part that I don't understand, is how do I only sum
tag_count for distinct playlists that are returned for that query.

In plain English, I am searching the PlaylistTag table by tag, and I
want to rank the results by which Playlist is most relevant for that
search by how many tags matched the query.

Does this make sense?

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