A harpsichord is a keyboard instrument that makes its sound by plucking a set of strings. In a harpsichord, depressing a key raises its back end within the instrument, which in turn lifts one or more jacks, each a thin strip of wood holding a small plectrum made from quill or plastic; each plectrum plucks a single string. The strings are under tension on a soundboard, which is mounted in a wooden case; the soundboard amplifies the vibrations from the strings so that the listeners can hear them. Harpsichord often include more than one choir of strings. Various devices are used to select which choir will sound when playing; these can include simple levers, or in more elaborate instruments the deployment of more than one keyboard.
The term denotes the whole family of similar plucked-keyboard instruments, including the smaller virginals, muselar, and spinet. The harpsichord was widely used in Renaissance and Baroque music, both for purposes of accompaniment and as a solo instrument. During the Baroque era, the harpsichord was a standard part of the continuo group. During the late 18th century, with the spread of the piano, the harpsichord gradually disappeared from the musical scene (except in opera, where it continued to be used to accompany recitative). In the 20th century, it made a resurgence, being used in historically informed performance of older music, in new compositions, and in certain styles of popular music.
The harpsichord was most likely invented in the late 14th century. The earliest instruments were quite small and sounded at relatively high pitch. By the 16th century, harpsichord makers in Italy had evolved a design that survived well into later centuries: lightweight instruments with thin case walls and low tension brass strings arranged in two choirs with a single manual. A different approach was taken in the Southern Netherlands starting in the late 16th century, notably by the Ruckers family. Their harpsichords used a heavier construction and produced a more powerful and distinctive tone with higher tension steel treble stringing. These included the first harpsichords with two keyboards, used for transposition.
The Flemish instruments served as the model for 18th-century harpsichord construction in other nations. In France, the double keyboards were adapted to control different choirs of strings, making a more musically flexible instrument (so-called 'expressive doubles'). Instruments from the peak of the French tradition, by makers such as the Blanchet family and Pascal Taskin, are among the most widely admired of all harpsichords, and are frequently used as models for the construction of modern instruments. In England, the Kirkman and Shudi firms produced sophisticated harpsichords of great power and sonority. German builders such as Hieronymus Albrecht Hass extended the sound repertoire of the instrument by adding sixteen-foot and two-foot choirs; instruments by the German builder Michael Mietke have recently served as models for modern builders.
Around the year 1700 the first piano was built by Bartolomeo Cristofori. In the piano, the strings are not plucked but rather are struck with hammers, which makes it possible for the player to control the volume of each note (in a harpsichord, a note sounds equally loud no matter how hard the key is pressed). With time and changes in compositional style, the expressive nuances made possible by the piano came to be increasingly valued, and by the late 18th century the piano (often called the fortepiano at that time) had largely supplanted the harpsichord. The harpsichord, now considered obsolete, almost disappeared from view for most of the 19th century. An exception was its continued use in opera for accompanying recitative, but the piano sometimes displaced it even there.
Twentieth-century efforts to revive the harpsichord began with instruments that used piano technology, with heavy strings and metal frames. Starting in the middle of the 20th century, ideas about harpsichord making underwent a major change, when builders such as Frank Hubbard, William Dowd, and Martin Skowroneck sought to re-establish the building traditions of the Baroque period. Harpsichords of this type of historically informed building practice dominate the current scene.
Harpsichords vary in size and shape, but all have the same basic mechanism. The player depresses a key that rocks over a pivot in the middle of its length. The other end of the key lifts a jack (a long strip of wood) that holds a small plectrum (a wedge-shaped piece of quill, in modern times often made of plastic), which plucks the string. When the player releases the key, the far end returns to its rest position, and the jack falls back; the plectrum, mounted on a tongue mechanism that can swivel backwards away from the string, passes the string without plucking it again. As the key reaches its rest position, a felt damper atop the jack stops the string's vibrations. These basic principles are explained in detail below.
The keylever is a simple pivot, which rocks on a balance pin that passes through a hole drilled through the keylever.
The jack is a thin, rectangular piece of wood that sits upright on the end of the keylever. The jacks are held in place by the registers. These are two long strips of wood (the upper movable, the lower fixed), which run in the gap between pinblock and bellyrail. The registers have rectangular mortises (holes) through which the jacks pass as they can move up and down. The registers hold the jacks in the precise location needed to pluck the string.
In the jack, a plectrum juts out almost horizontally (normally the plectrum is angled upwards a tiny amount) and passes just under the string. Historically, plectra were made of bird quill or leather; many modern harpsichords have plastic (delrin or celcon) plectra.
When the front of the key is pressed, the back of the key rises, the jack is lifted, and the plectrum plucks the string.
The vertical motion of the jack is then stopped by the jackrail (also called the upper rail), which is covered with soft felt to muffle the impact.
When the key is released, the jack falls back down under its own weight, and the plectrum passes back under the string. This is made possible by having the plectrum held in a tongue attached with a pivot and a spring to the body of the jack. The bottom surface of the plectrum is cut at a slant; thus when the descending plectrum touches the string from above, the angled lower surface provides enough force to push the tongue backward.
When the jack arrives in fully lowered position, the felt damper touches the string, causing the note to cease.
Strings, tuning, and soundboard
Each string is wound around a tuning pin (also known as a wrest pin) at the end nearest the player. When rotated with a wrench or tuning hammer, the tuning pin adjusts the tension so that the string sounds the correct pitch. Tuning pins are held tightly in holes drilled in the pinblock or wrestplank, an oblong hardwood plank. Proceeding from the tuning pin, a string next passes over the nut, a sharp edge that is made of hardwood and is normally attached to the wrestplank. The section of the string beyond the nut forms its vibrating length, which is plucked and creates sound.
At the other end of its vibrating length, the string passes over the bridge, another sharp edge made of hardwood. As with the nut, the horizontal position of the string along the bridge is determined by a vertical metal pin inserted into the bridge, against which the string rests. The bridge itself rests on a soundboard, a thin panel of wood usually made of spruce, fir or—in some Italian harpsichords—cypress. The soundboard efficiently transmits the vibrations of the strings into vibrations in the air; without a soundboard, the strings would produce only a very feeble sound. A string is attached at its far end by a loop to a hitchpin that secures it to the case.
Multiple manuals and choirs of strings