Use of thumb on low 'd' string
Playing and jamming difficulties...HELP ME!
@Floralin, I personally never use my thumb on the bass string, but I know some superb players who do so a lot. I also have one student who does it even on some of my own arrangements. The short answer is if it works for you, then it works for you.
One big issue when it comes to left-hand fingering is how the dulcimer is positioned on your lap. People who use their thumb a lot will want the dulcimer to be angled so that the lower bout is tight against their right hip and the head is angled out over the left knee (assuming you are a righty). Watch some of Guy-Babusek's videos here to see a good demonstration of that kind of positioning. That angle makes it much more comfortable to use your thumb (but much harder to use your pinky). People who don't use their thumb as much and rely more on their pinky move the head of the dulcimer in more so that the dulcimer is closer to being perpendicular to their legs. That positioning facilitates the use of the pinky. Check out Aaron O'Rourke's videos for an example of that, and notice that he also lifts the bottom of the dulcimer off his lap and angles it away from his body, something else that would make it harder to use your thumb on the bass string (and maybe the reason I never do it).
Personally, I use both my thumb and my pinky, and I shift the dulcimer on my lap depending on the fingering for any given song.
I am not sure which G chord you are talking about. In DAd:
I play the 3-1-0 G chord with my index on the bass string and either my ring finger or my pinky on the middle string.
For the 0-1-3 chord I use my ring or middle finger on the middle and my thumb on the melody.
For the 3-3-5 chord, I use either index, middle, thumb or middle, ring, thumb.
For the 5-3-3, I use index, ring, and pinky.
For the 5-6-7 chord I use either ring, middle, thumb or middle, index, thumb.
For the 7-6-5 chord I use either index, middle, pinky or index, middle, ring.
I'm sure there are other ways to get these chords (in fact, I know both Stephen Seifert and Aaron O'Rourke barre two of the strings when they play the 3-3-5 and 5-3-3 chords) but those approaches work for me, and in cases when there are more than one possibility, the context of the notes before and after will dictate which I use.
My advice is to do what works, but be aware that it might not work all the time, so be prepared to try other possibilities as well.
updated by @dusty: 06/21/20 06:40:39PM