drew Roberts has some spoken word works under the Creative Commons Attribution-ShareAlike license.
They can be found here: some of drew's stuff
Some people have made some music using some of these - look here for the music.
Loca Records releases all music on the label as CC-BY-SA (though there are some older works that are EFF Open Audio and GPL'd). Loca Records Website
The quick way into their downloads is Loca Music as MP3/Ogg
Scores and resources
The Choral Public Domain Library is a great resource for choral scores, texts, and translations, in a variety of formats.
The Mutopia Project contains classical scores under the CC-BY and CC-BY-SA license as well as public domain.