It could be that there was just a glitch in the system for a bit. I was able to find the site, and they say it is May 17-19. http://www.harpgathering.com/hg_home.htm
The link hasn’t worked for me either the past few days. It’s possible they’ve migrated to a new hosting service, and the new IPs haven’t fully propagated, so that some of us are able to connect and others aren’t. But, then again, I can’t discover any DNS entries for them at all. That’s very strange. The site does seem to have vanished entirely when browsing from Alabama.