How does a xylophone’s wooden bar produce sound when struck?

The xylophone is classified as an idiophone, a type of percussion instrument that produces sound through the vibration of its own body when struck.1

When a wooden bar is hit with a mallet, the material is set into vibration. The resulting pitch is determined by the physical characteristics of the wood, including its dimensions, density, moisture content, and modulus of elasticity. To refine the sound, modern xylophone bars are often shaped with a hollow groove cut along the underside, which helps align the bar's resonant frequencies to produce a clearer pitch.1234

Because the vibrations of a struck bar are naturally inharmonic, the instrument often incorporates tubular resonators or gourd resonators positioned beneath the bars. These resonators are tuned to the specific frequency of the bar, reinforcing the sound and helping to clarify the musical tone.34