MJ has an original Christmas song that he wrote for his family and all proceeds from that track, which you can buy on iTunes, goes to charity. I do not have MJ's song yet.
Dave has 2 Christmas songs from when he sang on tv and I have mp3's of those so if anyone wants them let me know. They aren't the best quality because ripping an mp3 from a video it's never usually very loud, but it works. :)