Every year, a number of musicians from around the world get together to create an album of Christmas carols using Garritan Orchestral Libraries music software. These vary from being very good, but still obviously electronic, to nearly indistinguishable from the real thing. Take a listen to the Monday link-of-the-day:

Garritan Community Christmas

So… The original link didn’t work any more, but all of that content plus a ton of other stuff is available on the Garritan SoundCloud site.