The xylophone makes sound, as similar to other percussion family instrument, by vibrating. To be more specific, when the mallet hits the bars, it makes the bars vibrate. From that vibration, it creates waves in the surrounding air, and finally, these waves are recognized as sound by humans' brain! It is so interesting to discover how these bars' properties are accountable for the pitch that they make. First, shorter, denser, and thinner bar makes higher pitch(I used to understand this as the other way around). In order to adjust the pitch, the bars need to be adjusted, according to its properties. To higher the pitch, I can make the ends thinner, or carve out a semi oval [or rectangle] section in the middle of the bars between the nodes, or shorter the bars. However, the density of the bars cannot be changed, since that's a permanent property of the material. I only have properties for pitches of rosewood, so I'll be using rosewood as the material for my xylophone. I will be constructing my xylophone by using wooden bars (lengths are according to the property table that I downloaded :D), and hammer them into a triangle wooden box.
Questions: How does the box underneath the bars amplified its volume? And why does longer bar has lower pitch? Please answer this (or show me how to find out the answer) asap, Ms. Écholsawnsome:)