What keeps a grand piano lid up?

Question

I am always amazed when the huge lid of my piano stays up by the prop of a little half-stick. What is the reason for this? How come it can hold up such a great weight?

Answer 1

The weight isn't as great as you seem to think; you could lift it single-handed. The little stick is strong because it's in compression.

The heavy part of a piano is the sounding board, a large metal casting on which the strings are mounted.