vibraphone -
A percussionmusical instrument with a double row of tuned metal bars, each above the tubular resonator containing a motor-driven rotating vane, giving a vibrato effect.
Wikipedia
The vibraphone, sometimes called the vibraharp or simply the vibes, is a musical instrument in the mallet subfamily of the percussion family. It is similar in appearance to the xylophone, marimba, and glockenspiel although the vibraphone uses aluminum bars instead of the wooden bars of the first two instruments. Each bar is paired with a resonator tube having a motor-driven butterfly valve at its upper end, mounted on a common shaft, which produces a tremolo or vibrato effect while spinning.
