The Vibraphone resembles the Xylophone in its general appearance,only its bars are made of metal and always has a resonating tube between each bar. At the top of each tube is a revolving disc,or fan, which rotates on an axle and powered by electricity which alternately opens and closes the tube. This causes the tone to "wobble". This special vibrato continues to sound long after the note has been struck. The speed of the fan can be controlled. Of course the vibraphonist can play the instrument without the use of the ":wobbling" effect.
There is a foot pedal,used to allow the notes to be sustained reminding one of the sustaining pedal of the piano. There is also a damping foot-operated pedal.
The vibraphone was designed in America sometime near 1920. In modern times its bars are usually made of a metal alloy which is lighter than steel and produces a mellow and sustained tone.
The range of the largest vibraphone is 4 octaves and is usually written at actual pitch.
The vibraphone is used in many modern small groups as the famous "Swing" groups but also by composers such as Alban Berg in his "Lulu" (1937). Its sweetest tones can be obtained by using soft-headed sticks. It can create special heavenly and enchanting atmospheres,can produce beautiful melodies or accompany lyric melodies with harp-like arpeggios or chords.
