Typically the Disney tunes are not directly linked to an album you can buy. With all the specialty albums, park albums and "bootlegs" out there, your best bet is to email the station manager (go to their station page for info) and ask them where the tune is from.
When you click "buy" it just does a search for whatever is entered for that song in the "album" field. Since much of the music is not from any particular album, this may not be very helpful. I try to enter all the info I have on the song (artist, where it's played, etc) in the player window, so you can search for more info if you want. Many of the songs are scrounged from here and there on the Internet.
Read the discussions here and you'll find some tricks!
Thanks for listening.
Andy @ RBV