Thank you for the review of the program. I was at the Appalachian Dulcimer Appreciation Day in Sperryville, VA, so I did not have the opportunity to watch it. My wife who was at home saw and recommends it highly as do you. I hope to use our Passport membership to watch sometime in the next few day. I appreciate your comments.
Ken
"The dulcimer sings a sweet song."
Thanks for all the added info, Wally! 
Last night we watched the full program from which the langspil video on YouTube was taken. The program is about contemporary "classical" music in Iceland.
It is a great integration of music, culture, and countryside. The level of expertise in scripting and performance is, in itself, amazing. You may not know that Iceland probably produces more skilled musicians per capita than any other country in the world. You've heard their as background on many films and videos.
There are several segments with the langspil in several settings, but that is only a modest portion of the program. The cello and percussion music takes up a lot more time. They don't mention the heavy metal and pop scene in Iceland, although that is also world class.
I was particularly enlightened by the discussion of parallel fifths singing and the use of changes in time signature on a measure-by-measure basis in folk derived music.
If you have PBS PASSPORT you can probably stream the program for free. It is also available on pay-for-view services.
I can strongly recommend this if you are interested in music beyond the dulcimer.
The footnote to the langspil video on YouTube says:
Watch full episodes and more: http://www.pbs.org/greatperformances Instagram: 
/ pbsgreatperformances Facebook: 
/ greatperformances Newsletter: https://www.pbs.org/wnet/gperf/newsle... #GreatPerformancesPBS
A very soothing, pleasant sound to my ears. Don't know the words, but it's nice nevertheless!
I suggest it is misleading to say that the Langspil is a "relative" of the dulcimer. The world has many three-stringed instruments which are plucked or bowed. I'm rather certain that many of them evolved independently.
People independently invent similar objects as solutions to a common problem. Would you say the heavy wooden hammer used to drive pegs for circus tents is a relative of a war club used by indigenous people in Tasmania? There are many conflicting patents for almost any device you can think of.
The Langspil is definitely descended from the Norwegian Langeleik. Iceland was "only a few days sail" from Norway back when both were part of Denmark's viking community.
https://en.wikipedia.org/wiki/Langspil
https://en.wikipedia.org/wiki/Langeleik
There is little evidence of overlap in Viking and Pennsylvania German communities in the 18th Century American colonies, although there were many inventive minds in both.
When you visit Iceland, you learn that in the early years ALL wood came from the sea (or was imported in longships.) As a result, they lived in some comfortable houses made from sod and burned peat.
That's an interesting video. Guitar makers have been using "sinker" wood for many years. This is wood cut from logs that have been submerged in rivers and harbors for years. The wood is dried, sawn into boards, and then dried some more. It is then sawn into thinner pieces for making guitars, ukuleles, mandolins, mountain dulcimers, etc. You can find many species of sinker wood for sale; e.g., cherry, cedar, redwood, mahogany, cypress, etc.
Ken
"The dulcimer sings a sweet song."
Interesting idea to make an instrument out of driftwood. For the last several years, luthiers have been using torrefied wood for soundboards. That process removes moisture to create wood that resists warping and improves the tone by mimicking the aging process. I wonder if using driftwood accomplishes similar goals. The langspil in that video sounds very nice. It has a clear, bright tone. Not much in the bass, but that could be due to the choice of string gauges rather than the resonant qualities of the wood.
Alex, you might like my discussion about the langspil in the "Dulcimer Ancestors" Group .
And here is the discussion in that group:
https://fotmd.com/strumelia/group_discuss/2169/icelandic-langspil
I have a beautiful custom langspil.
--> Note that you have to 'join' a Group in order to see all the replies to a discussion within the group. (joining and un-joining a group is easily done with a click)
This is really interesting:
