"I couldn't see anything about 'no PA' on the website, and I can't imagine an unamplified ceilidh, you'd have some confused dancers or a hoarse caller"Mo the Caller)

As has already been pointed out, the world that created the tunes we dance to at ceilidhs, and the danciung styles, had no PAs. Of course you can run festivals without PAs. And of course you can run festivals with PAs.What is intriguing is the hosatility that some people display to the concept of a totally acoustic festival. Granted, it wouldn't suit all puinters, or all performers, but it would suit a lot of folks. So why on earth not? It would good if there a few...it might catch on.
   I toured a barn dance/theatre show with Welfare State International once, throughout the northwest of England. While we did have a PA set up, to balance the band with some arrangements of strange instruments, the calling was done by Taffy Thomas, from the floor, no radio mics. Just talking to people, as you do. And the band played quietly. Lovely show.
    My own band, the Boat Band, play loads of totally acoustic gigs. All sorts of festivals.Some people like sitting hearing music acoustically, and I cant say I blame them.
No PA doesn't have to mean "quiet", either. Ever heard a samba band at a carnival?