Picture this: it's a quiet Sunday afternoon in New Ulm, Minnesota, about 1925. Looking forward to a bit of entertainment, the Larson family gathers around its Amberola model 50 cylinder phonograph (made about 1914 by Thomas A. Edison, Inc., in Orange, New Jersey). Arne B. Larson himself cranks up the phonograph so the family can listen to the nostalgic strains of tunes like "Just Before the Battle Mother," recorded on the blue wax cylinder. "Isn't it amazing how clear it sounds--