artists not showing up alphabetically and filters dont work

I’m doing some work on this page after inheriting it from another developer that left things a mess. It looks like everything is in place, but I cant figure out why the filters dont work and the artists aren’t sorting alphabetically. If anyone has any solutions I would really appreciate it!
The page is – http://staging.gatewayarts.org/artists/
and the code is – http://pastebin.com/zzQYrZvY