I like the idea in general, but the composition seems to complicated for me (I didn't read the last post by Erizon if that makes a difference). I don't like much the original artist being able to change every copy, nor do I completely like the editing or reproduction restrictions.
How about each "sheet music" item have its own info attached (rather than linked to the master).
As for copying/editing/redistribution restrictions, what about taking our cue from the creative commons license for the most part? All copies are marked as copies and the person who holds the master can choose to allow or disallow copying, or editing (though don't allow more changes than once or twice a day, please). Attribution would always be on (Original Composor: Erizon\n Contributing Composors (that is, people who edited this copy or parents of this copy before it was made): Nonea, Rajaaar). Redistribution/trading of copies could also be set.
How about each "sheet music" item have its own info attached (rather than linked to the master).
As for copying/editing/redistribution restrictions, what about taking our cue from the creative commons license for the most part? All copies are marked as copies and the person who holds the master can choose to allow or disallow copying, or editing (though don't allow more changes than once or twice a day, please). Attribution would always be on (Original Composor: Erizon\n Contributing Composors (that is, people who edited this copy or parents of this copy before it was made): Nonea, Rajaaar). Redistribution/trading of copies could also be set.