Howie Mitchell had a very nice demonstration of the various modes, as well as actually defining them, in his book on Apalachian or Mountain Dulcimer, that was published and sold by Folk Legacy; Carolyn and Sandy Paton, who hang aroound here now and then. An e-mail to either of them, or Googling "Folk Legacy" will get you to their web site, and you can ask if they have any intentions of releasing this training record or cassette and book, as a CD with the book.