Musical strings made from latex or other stretchy materials behave differently from non-stretchy strings. (You can read a detailed discussion here.) Their tone is virtually all fundamental, no overtones to speak of, and this gives them a round and punchy sort of sound. The photo here is of a latex-string zither, tuned diatonically over a three-octave range. Stretchy strings tend to be quiet, because they don’t vibrate forcefully enough to do a good job of driving a soundboard. Nor are they easy to put a conventional pickup on, for various reasons. For this instrument I assembled a specialized pickup arrangement, in which the bridge and the pickup are the same assembly: a guitar-style magnetic pickup is overlain with a spongy pad, on top of which sits a steel piece that serves as the saddle that the strings pass over. Because of the soft pad, the string vibration is enough to vibrate the steel saddle, and the magnetic pickup responds to the movement of the saddle. On this instrument there are two of these pickup/bridge assemblies. They’re positioned as middle bridges, allowing the string segments on either side to be played and heard.
In the audio clip, Spaghetti is heard in duet with itself.