The erhu is one of the most popular Chinese instruments. It has only two strings and a small resonator body covered with python skin. What makes it unique is that the hair of the bow is permanently threaded between the two strings. The player never removes the bow from the instrument; instead, they push the bow away from their body to play the outer string and pull it toward them to play the inner string. Since there is no fingerboard, the player must press the strings in mid-air to change the pitch, requiring incredible precision. Its sound is often described as melancholic and remarkably similar to a high-pitched human voice.