Jerry Rockwell is the mad scientist/genius of the mountain dulcimer, applying music theory to this simple instrument and exploding/exploring the possibilities within/without its structure. His "Eternal Cabbage" chordal exploration is a great exercise for playing and recognizing partial chords up and down the fretboard.
While you're over at his site, poke around and investigate some of the other pages too. Do it till your head hurts - then bookmark where you left off and come back for more. It's guaranteed to get you playing better/smarter in a heartbeat/New York Minute.
I have no idea what this/that is all about. Some kind of hidden theme - need more coffee to suss that out.