Have an uncommon yule with tools and music from the Commons.

That’s the pitch (so to speak) of the Ultimate Christmas Songbook, an iPad app built with 50 Christmas songs and a fully free and open source notation engine. Making use of public domain songs, the number of songs available continues to grow as the community contributes tunes. (Those contributors got the app for free.)

As notation proliferates on tablets, the app also suggests that “commercial” doesn’t have to mean “closed.” The scores themselves are available in open, cross-platform formats (MIDI, MusicXML, MuseScore, and PDF). But by generating revenues, the app can support further development – something that’s often been missing in open source music software projects.

And if you’re looking for a way to help family and friends play music, and they have iPads, the score reading features are quite reasonable. You get lovely display of scores, audio playback, tempo change, transpose, and the all-important font resize with reflow so you don’t have to squint.

The app is on iOS now, but other platforms are planned; an Android version is already in testing. And we hear lots more is coming from MuseScore, too, hot on the heals of a release that earned half a million downloads:
A Christmas update from MuseScore

More resources:
Open source code for mscore at SourceForge
Contributed scores to download
Ultimate Christmas Songbook, US$1.99 at iTunes
http://musescore.com/, software and community, including the desktop software for Mac, Windows, and Linux

For reference, here’s a look at how the desktop software works: