Development of Creative Commons licenses

[wiki_tomos <wiki_tomos AT inter7.jp>]

Hi. 

wrote: M Featherston <opensourcepro AT gmail.com>

>Maybe this is an old question that may have been dealt with before, but I
>noticed that Magnatune's catalog, or at least part of it, is licensed under
>the 1.0 version of the noncommercial-sharealike license. Isn't version
>1.0of this license incompatible with versions
>2.0 and 2.5?

I think you mean that works under 1.0 licenses cannot be switched 
to any later version, whereas works under 2.0 and 2.5 could be if 
you create their derivative works. 

4.b of CC-BY-SA 1.0 reads, for example, 
"You may distribute, publicly display, publicly perform, or publicly 
digitally perform a Derivative Work only under the terms of this License, 
and You must include ..."
http://creativecommons.org/licenses/by-sa/1.0/legalcode

4.b of CC-BY-SA 2.5 reads as follows:
"You may distribute, publicly display, publicly perform, or publicly 
digitally perform a Derivative Work only under the terms of this License, 
a later version of this License with the same License Elements as this 
License, or a Creative Commons iCommons license that contains the same 
License Elements as this License (e.g. Attribution-ShareAlike 2.5 Japan)."

http://creativecommons.org/licenses/by-sa/2.5/legalcode

Besides, CC-NC-SA 2.0 does not exist because all the standard 
CC license in 2.0 onward contains BY element. 

(You can see what's at the following two URLs
http://creativecommons.org/licenses/nc-sa/1.0/legalcode
http://creativecommons.org/licenses/nc-sa/2.5/legalcode )

For these reasons, you cannot mix two songs into one if one of them 
is under CC-NC-SA and the other some of the 2.0 or 2.5 licenses. 


Regards, 

Tomos