The Stick has been around for decades, and it is a specialized instrument for a player who has the finger-tapping technique needed to fully utilize its capabilities. Founded by Emmett Chapman, it is really a bass and guitar melded together, so it was one of the first modern stringed instruments that had greater than 6 strings. Most Sticks have 10 or more strings.
Because it uses so many strings and utilizes tapping techniques to create the sound, you get piano-like phrasing and harmony. Both hands can be used to create separate independent lines, much like a piano. Artists such as Tony Levin, Greg Howard, and Bob Culbertson have used the instrument to create amazing sounds and performances.
It’s clearly a modern instrument, founded well ahead of its time, requiring many techniques that came after the instrument was created.
And here is a video of Bob Culbertson playing The Stick. This guy is amazing to watch and listen to!