That is very insightful, thank you Grant!

Reading your perception of the differences it's pretty apparent to me that I am not at a level of knowledge yet to be trying to add in other equidistant strings. I think at the core, I am wanting to move towards all kinds of changes to improve my sound including chromatic scales, extra strings, and more elaborate courses, but probably the only one I am ready for yet is  more elaborate courses. I think at this moment I am mainly just considering any ways i can make the sound itself fuller or prettier, not necessarily ways to give it more notes.....yet!

Thank you for such a comprehensive response Ken. I guess I am mostly asking about different tunings to the courses but also dont really know if it makes more sense to just add extra strings in equidistantly. I'll try to notate the tunings more coherently going forward, I was not aware of the correct way to write them.

And yes 12 strings are a bit of a challenge for me but specifically my hands have gotten used to the freedom of sliding around and only having to stay over 1 string per finger while they do. So i have gotten used to hand positions that put pressure in the exact place on the string that I need, and when another one is added in, my muscle memory doesnt compensate for having to move my finger slightly to the side well enough. That being said if I can find a tuning that has a sound I really like, it would be a pleasure to put in the practice.

Anyway, I am very curious  if you can still use DAd tabs with the tunings you mention? Will they still sound correct? I have a hard time understanding how our ears interpret these intervals but intuitively it seems like if your melody string was Ad it would change some chords. Is this the case? Also if the middle string is tuned 'Aa' (which I think is A3a4) then the highest pitch open string would be the middle correct? Does this affect the way the sound is perceived if the melody you are fretting is lower in pitch than the drone, instead of typically always being higher? Again, to be clear, this is all coming from an uneducated perspective.

updated by @nate: 05/06/20 02:49:11PM

Interesting question Nate! First about 6 string dulcimers and things: I have a mcspadden baritone with 6 strings. Before I restrung it, it was A2A3-E3E4-A3A3. I also thought it was a little annoying to play, since the pairs of strings are not equal in size. But I thought it had a very rich sound with the octave courses.

Then you're also talking about some 4 string ideas. I think those are fun. However, going off what Ken was saying, a 4 string dulcimer is not really a "trational" dulcimer. You'll have to do more chords usually and be more careful what strings you play.

A few different tunings:
D-F#-A-d:
I haven't done much with this but I think most of the time, folks are using this to access more chromatic notes on a diatonic instrument. If you're not familiar with chromatic stuff, this probably won't be very intuitive.

D-G-A-D:
This is the first 4 string tuning I really tried. I also played Rondo Alla Turca with this tuning. I think it's more intuitive, because both DAd and DGd are hidden in there. I also like it because you can get more 4 note chords in a tighter range, and have extra strings for fast melodies. However, this tuning is harder with strumming because one of the middle strings will often get in the way.

D-A-d-a:
I of course like this tuning. It's got a larger range, but with four strings more 7th chords and other 4 note chords are avaliable. Another observation to help playing in this tuning: the higher three strings, (A-d-a) are actually the same intervals as DGd tuning. If you know DGd chord shapes, you can play them there.

One thing to think about is what you want extra strings for. Do you want to play songs you already know, just with a different sound; or do you want to dive into a completely new tuning and different techniques?

Grant

You don't seem to be talking about adding additional strings, just about changing the same six strings to different tunings.  Two different things.  

FWIW -- mostly we refer to tunings from the bass string to the melody, not melody to bass the way you write them...  Tunings are usually written  DAA, DAd, etc, where the lower case letters show a note an octave higher -- d versus D

Remember, the dulcimer is a 3 course instrument -- melody, middle drone, bass drone -- not a 6 course instrument like a guitar.  Any course can have 1, 2 or even 3 strings, but we still retain the concept of melody, middle drone and bass drone strings.  MOST dulcimer tunings involve the bass and middle drones being tuned a fifth apart, with the melody string(s) tuned to create different "scales" as the guitarists call them.  D-A or C-G or G-D are fifths apart 1-5.  Tuning the melody strings to different notes gives us scales-- 1-5-5. 1-5-7, 1-5-8, 1-5-4 etc.  -- which start at different frets.  

If you think strumming a 3-course dulcimer with 2 strings per course (total 6 strings) is "very cumbersome to get used to fretting..." and you're not getting "all that much fuller of a sound" -- them you're really in trouble if you try to strum a 6-course doubled string instrument like a 12 string guitar.  

A 3-courses double strung (6 string dulcimer) tuned with some octave pairs and other combinations are not uncommon.  Bass courses strung and tuned Dd are very common.  So are melody course tuned Ad.  Thus you have Dd-AA-Ad.  Once in awhile you'll find someone experimenting with octave tuned middle drones Aa and you could have Dd- Aa-Ad.  Any of these octave tuned couplets would need something other than the ordinary set of dulcimer string, of course.

I'd like to put more strings on my next dulcimer. I have a 6 string dulcimer which is tuned dd-AA-DD. Very cumbersome to get used to fretting those extra strings and not all that much 'fuller' of a sound in my opinion. @Granto has one which I've seen in his videos that is tuned D3 A3 D4 A4 which I'd love to do eventually but for now I gotta study theory more so I can actually get some use out of the extra range. The same goes for adding an f# string as in d-A-F#-D Someone mentioned on here a dulcimer tuned dd-a-Dd with a D4 string running in course with the D3. That's hard to wrap my head around.I am aware that 12 string guitars often use 'octave tuned' courses, but It seems to me that this might get in the way. For example 'dyad' chords which only use the middle and bass string would still have those high notes that you are meant to be specifically avoiding playing. Also I'd imagine the bridge would have to be cut bizarrely for better intonation. What do y'all think? Have you heard dulcimers tuned like this? Are you aware of specific issues in building or playing that relate to adding extra strings? What do yall think is an ideal 'extra' string or strings to add to a dd-a-D dulcimer? Finally what about these two extremely radical tuning ideas: d4d4-A3A3-D3D2 as well as d4D3-A3A2-D3D2 basically, all three strings running in course with their lower octave. Conceptually i would think it would sound good but I have no education in music or building so It might very well be muddy or chaotic or impractical. I'd love to hear thoughts!

updated by @nate: 05/07/20 11:38:18AM