This is the ancient Bowed String Musical Instrument from Northern Europe
The Taglharp, Tahlharp or Jouhikko is an ancient musical instrument typified by the component parts of three long strings, individually stretched across a long wooden structure, from a tuning peg at one point, over a bridge, and secured at a "tail" end point; these were played with a stringed bow with one hand, while the other hand touched the strings of the instrument at various points to produce musical notes.
The origin of this musical instrument have been attested to in various documents, including Roman military documents as old as 30 BCE ; one such entry gives information about "barbarians" performing "war trance" music about a sacred tree with musical notes played upon instruments crafted of "tree boughs" and "horse hair."
Russian and other Eastern European archeologists have discovered evidence of this musical instrument that can be dated as far back as 3400 BCE, and have speculated it may be nearly as old as the development of the ancient horse cultures in the regions of the Ukrainian & Russian Steppes (around 5000 BCE).
A tutorial for the creation of one popular version of this instrument:
Most Commonly Known as the Taglharp (horse "tail harp") & the Jouhikko...
"Jouhikko" is the name commonly used by the Finnic peoples. Scandinavians call it Taglharp; in Estonia this instrument is commonly called Talharpa (both names mean "tail harp")... It has existed among the Northern Germanic, Scandinavian, Finnish, and Slavic peoples in many different forms over a period of thousands-of-years. It was an innovation from ancient Proto Indo-European Bow-&-Arrow Horse Cultures. The fundamental design features of this instrument include two-or-more (typically three) music Strings of horse-tail, attached at the top to tuning pegs, and at the bottom to a "Tail" piece with a Bridge somewhere in the "middle". The sound is achieved when Strings are played with an arched Bow (also with horse-tail string) through a hollowed-out "Soundboard" & "hole/s". The melodies are played with the hand opposite of the hand holding the "Bow"; through a large open area at the top of the instrument fingers are pressed against the Note Strings. It is a very simple and ancient sounding instrument that has been gaining in a resurgence of popularity. The Taglharp has been featured prominently with popular musical artists from Italy, Russia, Scandinavia, and many other countries including North America...