If you want a bit of musical accompaniment when you go carol singing this year, then add the MIDI Christmas Collection to phone.
The collection includes 66 different Christmas classics, all in MIDI format, for you to transfer to your phone for use as ringtones, or just to play to get you in the festive mood. When you extract the Zip file you'll notice that the music is divided into two folders: 'Internationales' and 'Nacionales'. I'm not quite sure where the distinction comes but it's a nice selection anyway.
The music in MIDI Christmas Collection is generally of decent quality, with most of them a jazzed-up version of the original perfect for polyphonic devices. What's more, each track is of full length, rather than just a snippet from the original song.
On the downside, the names of the files in MIDI Christmas Collection are quite ambiguous. It's very difficult to work out what each one is just by looking at its shortened name, or the name it goes by in its original language.
Still, if you want to put yourself in a Christmas mood, then spend some time flicking through the MIDI Christmas Collection on your phone.