I first heard the Anonymous 4 on KUSC Classical (91.5 Southern California) many many months ago.
I typically run without any music, I'm somewhat of a minimalist/purist in that category. But I recently put on my shuffle for a long road run (read: boring...I hate running road) and listened to their 2008 album Miracles of Compostela on repeat. What a run....
Now I'm not a Christian, but if the songs of these four women don't convert me...
Here's a youtube clip of them.