Swedish origins of the dulcimer?
Found an interesting article arguing for the Swedish origins of the dulcimer.
Nils R. Caspersson, "Diatonisk and the Dulcimer." Voices: The Journal of New York Folklore 34: 3/4 (Fall 2008): pp. 28-34.
I am unsure of the legality of posting copyrighted articles when the publication of out-of-print, but perhaps you can find a copy for yourself through your library. The article has been scanned and is available in Proquest.
Much of the evidence Caspersson cites is coincidental, such as the number of Swedish immigrants in Kentucky and Tennessee, or the similarity between the Tennessee music box and primitive psalmodikons. Perhaps the most compelling evidence he cites is that the psalmodikon has a raised fretboard, whereas the German sheitholt does not.
He also refers to a three-stringed moraharpa dating from the 16th century, which he thinks was tuned DAD and based on a diatonic key pattern. He provides no evidence for that tuning, however.
Anyway, it's an interesting article with some cool tidbits of information (such as the Swedish Lutheran church banning the fiddle in the early 19th century because it led to dancing -- gasp!).