Vibraphone Vibraphone The vibraphone (also known as the vibraharp or simply the vibes) is a musical instrument in the struck idiophone subfamily of the percussion family. It consists of tuned metal bars, and is usually played by holding two or four soft mallets and striking the bars. A person who plays the vibraphone is called a "vibraphonist" or "vibraharpist". The vibraphone resembles the xylophone, marimba, and glockenspiel, one of the main differences between it and these instruments being that each bar is paired with a resonator tube that has a motor-driven butterfly valve at its upper end. The valves are mounted
Post Instrument or three operators, one operating the Post Instrument, another using the telephone to report the locations to a plotting center, and the third, if present, operating as a lookout and helper. The original Post Instrument was supported by a metal rod extending vertically from the center of a circular table. A small section of map showing the surrounding area was attached to the tabletop. The instrument itself consisted of an open rectangle of metal bars, with the long axis horizontal. Hinges at the connection points between the bars allowed the bars to be rotated to form various parallelograms. Similar hinges