Trivia
The vibraphone and its spinning fans

The vibraphone, whose tone plates are made of metal, produces, once struck, notes that last a long time and disappear gradually. However, there is a lack of the density of wood, and the bars are uniform, which results in the sound that is produced sounding non-organic. To add variations to the notes, the instrument is thus built with vibrating fans that add a vibrato effect. Above the resonator pipes runs an axis with numerous fans attached. The flow of electricity along this axis makes the fans spin, repeatedly opening up and then closing off the pipes. The sound grows louder when the resonators are open, giving rise to waa-waa shifts in the notes. The rotation speed can be sped up or slowed, allowing the player to produce the intended amount of vibrato.
The damper is used to halt the long-lasting ringing of the notes. When a pedal is released, it touches the tone plates, stopping the vibrations. Both the fans and the damper are mechanisms that the marimba-whose notes do not last so long-does not have.