or vibraharp
Percussion instrument with tuned metal bars, arranged keyboard-style like the xylophone .
Felt or wool beaters are used to strike the bars, giving a soft, mellow tone quality. Each bar has a resonating tube suspended vertically below it to sustain the tone; small electrically powered spinning disks at the top of the resonators produce a vibrato effect by rapidly closing and opening the resonators. Invented с 1920, it soon became a popular jazz instrument.