If you want to stick with Pandora, try looking music by Alan Menken. My DD finds a good variety of Disney music with that "station" on Pandora. It isn't necessarily parks' music, though.
I have had less luck with the Sherman Brothers "station". I like the "old school" Disney music (as I tried to explain to DD!) but Pandora kept giving me 40s music that wasn't Disney-related at all!
I do like the MouseWorld Radio app, too, for park music.