The most recent addition to the repertoire of orchestral percussion instruments is the vibraphone (also known as the vibraharp or vibes), with its early origins dating back to the vaudeville era of the 1920s.
The onomatopoeic name vibraphone refers to the vibrating sound of the instrument and derives from the Greek phoné (sound) and Latin vibrare (vibrate, tremble). This young instrument is a metallophone based on a metal marimba with resonators and an electric motor. Its vibrating tone draws its influence from the human voice. Of all mallet instruments, the vibraphone is the most mechanically complex.
Timbre and sound
A spectrum of timbres, from dark and mellow to shiny and light, can be produced by the vibraphone. The sound comes from a series of tuned tone bars struck by mallets, with a general range of three to four octaves.
Manufacturers use aluminum for these bars because it has a much longer decay time than the wood or synthetic wood products used in the marimba or xylophone bars. Metal resonators, sometimes called “resonator tubes” or “resonator pipes”, are suspended beneath the tone bars. The length of each resonator varies depending on the pitch of the tone bar; the lower the note, the longer the resonator.
One of the most distinguishing characteristics of a vibraphone’s sound comes from the spinning motor-driven disks, called “fans”, at the top of each resonator. This causes a slight fluctuation of the pitch once engaged, resulting in a vibrato effect, along with a change in volume, resulting in a tremolo effect. This become more pronounced as the speed of the motor changes from slow to high.
Vibraphone mallets usually consist of a rubber ball core wrapped in yarn or cord, attached to a narrow dowel. The latter is most commonly made of rattan, birch, fiberglass, or nylon.
Suitable mallets for the vibraphone are also generally suitable for the marimba. The mallets can have a great effect on the tonal characteristics of the sound produced, ranging from a bright metallic clang to a mellow ring with no obvious initial attack. Consequently, a wide array of mallets are available, with variations in hardness, head size, weight, shaft length, and flexibility.
The vibraphone owes the great resonance of its notes to the damper pedal. This pedal operates a bar of felt, which removes itself from the bars when the pedal is pressed. When releasing it, the felt strip presses against the metal bars, damping them. The mechanism works the same way as in the piano.
Tuning of the vibraphone
The standard modern vibraphone has a range of three octaves. They begin on the F below middle C to F6 in scientific pitch notation. Larger 3 1⁄2- or 4-octave models that begin at the C below middle C are also becoming more common.
Unlike its cousin, the glockenspiel, this is a non-transposing instrument, generally written at concert pitch. However, composers occasionally write parts to sound an octave higher. Generally, modern vibraphones tune to 442 hertz equal temperament. However, vibraphone makers produce instruments in various tunings since orchestras in different parts of the world require them.