Just like to put my two penn'th in about this thread.
I don't like to comment on these arguments normally, as I do not get around as much as I should(She won't let me out will she Steve!), but looking at the flyer for the venue it does say Northern Soul, and it does also mention the main, early, (i.e. pre 1981 venues), and therefore does not indicate a cutting edge "rare soul", "modern soul", "tent music" scene. If I were to attend, I would expect old style northen(including Mecca type '70s), and not a night of disco , slow funk, rock & roll, or feckin' beat ballads for that matter.
Why not split the whole scene into the 27 factions it appears to be nowadays and go into your own little underground cults..... or maybe learn to live together.
Or even just go to the events that appeal to your musical taste & let the others do the same.
Paul