I will be on air tomorrow, doing the all-Christmas edition of Divaville, from 3-5 pm eastern time. 88.7 if you're local, wxdu.org if you're not.
This year's show will focus on "Christmas obscura," (apparently this is the music geek term for obscure and sometimes weird old Christmas music) because that's mostly what I've been listening to this holiday season. My early favorite is "The Bell That Couldn't Jingle," an obscenely catchy and strangely literal tune about a bell that couldn't jingle, until Santa gave it a new ringer. At which point it could again jingle.
In case you can't listen tomorrow afternoon but you're still interested in weird and wonderful old Christmas music, here are my favorite online sources. All free, but the download facility kind of sucks unless you pay for premium.
http://www.falalalala.com/
http://ernienotbert.blogspot.com/
http://musicyouwont.blogspot.com/
By "old Christmas music" do you mean real early music, or just older popular music that's fallen off the playlists at the mall? Because I've got a decent collection of early music Christmas stuff; right now I'm listening to a set of medieval carols performed by the Oxford Camerata. It's too late to do anything this year, but if you'd like some of it for next year's show, we can negotiate after the holiday crunch is over.
by "old" I mean from early in the previous century, not the previous millenium :) Divaville is a show of jazz and pop standards from the 30s - 50s, which I sub from time to time.
Do you have download links to your show yet? Are they publically available?