You guys are going to have to do better than "they make musical instruments out of wood". Well, yes. And they DON'T make bells out of wood, for very obvious reasons. Any body can show this. What is going to hold a standing wave longer? Wood or metal? And let's stay within the materials used to actually make something resembling a tonearm.
All of those curved arms, damping material added to metal tubes, damping troughs and fluids. Why was all of this developed? Because of standing waves in metal parts.