currently, i don't think the "_validate_auth_header()" function is working as expected...

https://github.com/metabrainz/listenbrainz-server/blob/master/webserver/views/api.py#L108

if you omit the "Authorization" header completely, it returns HTTP status 0 with no response text.
if you include the "Authorization" header but with no token, it also returns HTTP status 0 with no response text.

and if you omit the "artist_name" or "track_name" parameters, you do get a meaningful error.. but it's returned as HTML. it should be JSON.