by pml » Thu Oct 30, 2008 9:26 pm
Simply, you'll have to ask the rights holders to see if they would be willing to allow the works to be issued under one of those licences.
Who those rights holders are you will have to find out; sometimes it is the estate of the deceased composer; or the rights of the composer may have been transferred to a publisher. In the latter case, it is unlikely you will be given permission. Also, you may have to establish the rights holder on a work-by-work basis; composers often use many different publishers, and the rights may not have ended up being transferred to a single publisher.
Assuming you do contact the rights holder: they might not already be aware of the Creative Commons movement, and might therefore be hesitant to alter the copyright status of the works (as in what those rights allow you to do). They may answer saying they wish to obtain legal advice to ascertain the impact of adopting one of the CC licences (which possibly would be at your cost if you wish to proceed).
You won't know until you try. It helps to be polite, well-informed, and diplomatic. Best of luck.
Regards, Philip