david moon
Attempting the Blues
There is this acoustic instrument called the Tiple. It is generally in the Uke size range, but I have seen bigger. It has 4 "courses" of strings. The lower and upper are doubled like a 12-string. The middle two have three strings tuned to the same note and different octaves. It seems to be more a Central or South American thing but Martin made them. And you can find lots of videos online.
Here's one
Here's one