Sam, have you heard of "The Trans-Siberian Orchestra"? They have a couple albums out, best is "Christmas Eve and Other Stories." It tells a story of an angel sent down to earth on Christmas Eve to find the perfect "gift" that we humans have made in the name of Christ. The music is mostly rock and includes both traditional songs and new compositions which tell the story. The new songs often incorporate traditional carols. And there's an instrumental medley of "O Come All Ye Faithful/O Holy Night" done with screaming heavy metal guitar.
Check it out.
SD
I do indeed know of Trans-Siberian Orchestra and have both their Christmas albums. The style of music reminds me of Meatloaf, but they are so much better. With each listen, the music grows on you. Great liner notes too. My pet peeve with many albums is the lack of liner notes. If the music industry doesn't want us downloading off Napster, give us some meat to go with the packaging! Make it worthwhile to get the album and great liner notes and cover art help do that.
BTW, TSO has a third album out called "Beethoven's Last Night." It's not a Christmas album but I recommend it.