I guess everybody knows about the FZ Movie Kickstarter campaign.
The final part of the Kickstarter campaign could be followed live on Youtube during which Joe T. pulled some nice finds out of the vault.
The most impressive one was 'The Fly'. Three (or four) pieces that Zappa wrote as a possible soundtrack for the 80's movie with the same name.
The same session also featured Ahmet telling that he had heard that Frank turned down writing the soundtrack for "Star Wars".