It's taken me months to realise that the title is open to misinterpretation, which perhaps is why some people objected. It might suggest that the organisers pick the guests they want at their milonga – which would be gross. 'Him, oh yes, he can come. But not that friend of his, no way. & she's all right, but isn't there anyone better?' I hope my description of the milonga left it clear that invitation is by personal recommendation: people recommend friends, and the organisers invite everyone recommended. My title might have given the wrong first impression.
Once again, I think it's a pity it's necessary to resort to this so we can enjoy a good afternoon of dance. But organisers here don't have the kind of authority some of them have in Buenos Aires, and the dance isn't generally understood or respected here in the way it is there. There are people here who've watched a few TV dance programmes, taken a few tango classes and go out and don't even notice how much disturbance they are causing. They probably think they are bringing a bit of life into a boring evening. All these couples making their way slowly round the room; let's barge into them, wake them up a bit!
There's also another slightly different system here: there are a few milongas that are open to all, but aren't advertised. You hear about them by being on a mailing list. This has a similar effect. There's a bit of a 'tango underground', but I can't see anything wrong with that, except that it's much harder for the organisers to make ends meet without open access and advertising. They do it because they enjoy a certain kind of milonga: in the circumstances the guest list is the only way to make it happen.