Don't Sit Under the Apple Tree
My dulcimer does chord-melody, Andrews Sisters-style, on "Don't Sit Under the Apple Tree." Tuned DAd. No extra frets are used in this arrangement.
In honor of the upcoming 70th anniversary of the D-Day landings.
(Actually, this arrangement is also partly inspired by an arrangement of "Bye Bye, Blues" I heard from a dulcimer player named JD Labash in about 1981. I haven't heard his name since, but it made an impression.)