Mountain dulcimer

From WWR

The mountain dulcimer is a fretted string instrument with three or four strings, though modern versions of the instrument can have as many as twelve strings and six courses. The body extends the length of the fingerboard and traditionally has an hourglass, teardrop, triangular, or elliptical shape. The traditional way to play the instrument is to lay it flat on the lap and pluck or strum the strings with one hand, while fretting with the other. A variant called the courting dulcimer has two fretboards, which allows two players sitting across from each other to perform duets. The frets are arranged in a diatonic scale, and this helps to give the instrument it's distinctive sound.