We just supported OpenScore: OpenScore will digitize and liberate all public domain sheet music, including the classics of Mozart, Beethoven and Bach. The community aims to transfer history’s most influential pieces from paper into interactive scores which you can listen to, edit and share. Scores are released under Creative Commons Zero, allowing unlimited copying, adapting and sharing.

Almost there!

https://www.kickstarter.com/projects/openscore/openscore-join-the-sheet-music-revolution