I've got to agree with pat on this one. I've nothing against Carnival of the Animals and Saint-Saens, but that's too melancholy for my liking. It doesn't suite MA3 at all IMO, - sorry! ...
It worked for Harry Potter, but I don't think it would work here.
I've recommended this a few times before, but if you want an appropriate tune for a screensaver, then try 'The Blue Danube' with the Sharks' 'Ray O'light' tank filled with Manta Rays!