Ah Sidmouth,
We'll be their and if it's as good as usual it will be far more fun than the eclipse - I'll wait for the next one to come to the UK:-). Prepare for long days and early mornings - you may find yourself getting up before you go to bed!
Finally I've never met anyone who has been there that didn't enjoy it - whether playing or listening. The Areana is one of me favourite haunts - all those instruments etc.... plus a beer tent.
Have a good time, and if your still around in Sept. why not pop into the Fylde Folk Festival. at Fleetwood Lancashire. that's fun too (and the only dark skys you'll see there is if it rains!!!!!)
Take care and sing well
Pete