Jean and Pam Simmons also recorded, in addition to the ones mentioned by Harpgirl, Stone County Dulcimer and Ozark Mountain Dulcimer. These were from early 1970s I think. Howie Mitchell recorded an influential dulcimer album on Folk Legacy in the 60s, if memory serves correctly. Frank Proffit also recorded for Folk Legacy using the dulcimer. Paul Clayton had an early dulcimer album on Folkways. The Russell Family recorded a dulcimer album for County sometime in the 60s as well. There are some Library of Congress recordings with dulcimer that may predate 1940, but the only one I can remember, at the moment, is I.G. Greer and his wife. Greer was a professor at Appalachian State in North Carolina. I think he was on several Folkways anthologies. There was also another album from the early 70s from National Geographic with a dulcimer selection from none other than ole Arkie.