Try http://www.greendragonhardraw.co.uk/
The landlord is having probs with the website at present - but keep an eye on it for an update.

Dates of this year's are as Gerry posted above (27th-29th July)
and this small but vibrant fest centres entirely round the hugs pub - the Green Dragon.
It's mostly free and very participant orientated (singers/musician sessions, dance teams etc)
Only the eve concerts to pay into (optional!)

This year sees the great Dave Burland in concert for a start!
I'll post more, soon, when I find out who else.....
Cheers - Duncan