I could make the first entry a keyed entry i.e.

MUSICBRAINZ_SERVERS = [
    'MainMBServer' : 'musicbrainz.org',
    'beta.musicbrainz.org',
]

but I am not sure what the impact would be of mixing keyed an unkeyed entries below:

        self.ui.server_host.addItems(MUSICBRAINZ_SERVERS)

What order would the dropdown list be in?