Grades K–2 · Arts & Music
Why do a marimba’s wooden bars play different notes?
A marimba can make a row of different notes from wooden bars. When a bar is struck, it bends back and forth very quickly. The moving wood pushes the nearby air, helping send sound outward.
In the diagramDifferent tone bars support different vibrationslower noteshigher notesBar shape, material and resonator tubes also matter; no exact pitches shown.
Different bars vibrate at different rates. The longer bars in a marimba generally make lower notes, while shorter bars make higher notes. Makers also shape the wood underneath. A bar's size, shape and material work together to determine how it bends and vibrates.
Air inside a tube beneath the bar can vibrate along with it. The tube is chosen to respond strongly near the bar's note, helping the instrument send that sound into the surrounding air. Striking harder usually makes a stronger sound, but it does not make the bar longer or shorter. How loud the note is and how high it sounds remain different features.
About this explanation
Starting knowledge: Know that a vibrating object can make sound and distinguish a higher note from a louder sound.
Sources
- Yamaha — The Structure of the Marimba: What kind of instrument is the marimba?
- Yamaha — There is craft to the design of the tone plates, too
- Yamaha — Inside and Outside the Resonator Pipes