Piano

A "baby grand" piano, with the lid up. Most pianos are about 150 cm wide. Baby grands such as this are about as long as they are wide, but a concert grand can measure up to 3 m perpedicular to its keyboard.

A piano is a musical instrument that is classified as a keyboard, percussion, or string instrument, depending on the system of classification used. Playing the piano is wide-spread in western music for solo performance, chamber music, and accompaniment, and is also popular as an aid to composing and rehearsal.

The piano produces sound by striking steel strings with felt hammers. Vibrations are transmitted through the bridges to the soundboard.

The word piano is a shortened form of the word pianoforte, which is seldom used except in formal language and derived from the original Italian name for the instrument, gravicembalo con piano e forte (literally harpsichord with soft and loud). This refers to the ability of the piano to produce notes at different volumes depending on how hard the keys are pressed.

As a keyboard stringed instrument, the piano is similar to the clavichord and harpsichord. These three instruments differ in their mechanisms of sound production. In a harpsichord, strings are plucked by quills or something similar. In the clavichord, strings are struck by tangents, which remain in contact with the string. In a piano, the strings are struck by hammers which immediately rebound, leaving the string to vibrate freely.

Early history

Bartolomeo Cristofori of Padova, Italy, invented the first pianoforte. He called it a gravicembalo con piano e forte. It is not entirely clear when he built this instrument, but an inventory made by Cristofori's employers, the Medici (pron./'Medici/) family, indicates the existence of an early Cristofori instrument by the year 1701. Cristofori built only about twenty pianofortes before he died in 1731; the three that have survived until today date from the 1720s.

Like many other inventions, the pianoforte was founded on earlier technological innovations. In particular, it benefited from centuries of work on the harpsichord, which had shown the most effective ways to construct the case, soundboard, bridge, and keyboard. Cristofori, himself a harpsichord maker, was well acquainted with this body of knowledge.

Cristofori's great success was in solving, without any prior example, the fundamental mechanical problem of piano design: the hammers must strike the string, but not touch it once they have struck (which would damp the sound). Moreover, the hammers must return to their rest position without bouncing violently, and it must be possible to repeat a note rapidly. Cristofori's piano action served as a model for the many different approaches to piano actions that followed. Cristofori's early instruments were made with thin strings and were much quieter than the modern piano. Compared to the clavichord (the only previous keyboard instrument capable of dynamic nuance), however, they were considerably louder and had more sustaining power.

Cristofori's new instrument remained relatively unknown until an Italian writer, Scipione Maffei, wrote an enthusiastic article about it (1711), including a diagram of the mechanism. This article was widely distributed, and most of the next generation of piano builders started their work as a result of reading it. One of these builders was Gottfried Silbermann, better known as an organ builder. Silbermann's pianos were virtually direct copies of Cristofori's, with one important addition: Silbermann invented the forerunner of the modern damper pedal (also known as the sustaining pedal or loud pedal), which lifts all the dampers from the strings at once. Virtually all subsequent pianos incorporated some version of Silbermann's idea.

Silbermann showed Bach one of his early instruments in the 1730s, who did not like it at that time, claiming that the higher notes were too soft to allow a full dynamic range. Although this earned him some animosity from Silbermann, the criticism was apparently heeded. Bach did approve of a later instrument he saw in 1747, and even served as an agent in selling Silbermann's pianos.

Piano-making flourished during the late 18th century in the Viennese school, which included Johann Andreas Stein (who worked in Augsburg, Germany) and the Viennese makers Nannette Stein (daughter of Johann Andreas) and Anton Walter. Viennese-style pianos were built with wooden frames, two strings per note, and had leather-covered hammers. It was for such instruments that Mozart composed his concertos and sonatas, and replicas of them are built today for use in authentic-instrument performance of his music. The pianos of Mozart's day had a softer, clearer tone than today's pianos, with less sustaining power. The term fortepiano is nowadays often used to distinguish the 18th-century instrument from later pianos.

Development of the modern piano

Piano hammers

In the lengthy period lasting from about 1790 to 1890, the Mozart-era piano underwent tremendous changes which led to the modern form of the instrument. This evolution was in response to a consistent preference by composers and pianists for a more powerful, sustained piano sound. It was also a response to the ongoing Industrial Revolution, which made available technological resources like high-quality steel for strings and precision casting for the production of iron frames.

Over time, piano playing became a more strenuous and muscle-taxing activity, as the force needed to depress the keys, as well as the length of key travel, was increased. The tonal range of the piano was also increased, from the five octaves of Mozart's day to the 7 1/3 (or even more) octaves found on modern pianos.

In the first part of this era, technological progress owed much to the English firm of Broadwood, which already had a strong reputation for the splendour and powerful tone of its harpsichords. Over time, the Broadwood instruments grew progressively larger, louder, and more robustly constructed. The Broadwood firm, which sent pianos to both Haydn and Beethoven, was the first to build pianos with a range of more than five octaves: five octaves and a fifth during the 1790s, six octaves by 1810 (in time for Beethoven to use the extra notes in his later works), and seven octaves by 1820. The Viennese makers followed these trends. The two schools, however, used different piano actions: the Broadwood one more robust, the Viennese more sensitive.

By the 1820s, the center of innovation had shifted to Paris, where the Erard firm manufactured pianos used by Chopin and Liszt. In 1821, Sebastien Erard invented the double escapement action, which permitted a note to be repeated even if the key had not yet risen to its maximum vertical position, a great benefit for rapid playing. As revised by Henri Herz about 1840, the double escapement action ultimately became the standard action for grand pianos, used by all manufacturers.

Some other important technical innovations of this era include the following:

use of three strings rather than two for all but the lower notes
the iron frame. The iron frame, also called the "plate", sits atop the soundboard, and serves as the primary bulwark against the force of string tension. The iron frame was the ultimate solution to the problem of structural integrity as the strings were gradually made thicker, tenser, and more numerous (in a modern grand the total string tension can approach 20 tons). The single piece cast iron frame was patented in 1825 in Boston by Alpheus Babcock, culminating an earlier trend to use ever more iron parts to reinforce the piano. Babcock later worked for the Chickering & Mackays firm, where the first iron frame in grand pianos (1843) was developed.
felt hammers. The harder, tauter steel strings required a softer hammer type to maintain good tone quality. Hammers covered with compressed felt were introduced by the Parisian maker Jean-Henri Pape in 1826, and are now universally used.
the sostenuto pedal (see below), 1844 by Jean Louis Boisselot and improved by the Steinway firm in 1874.
the overstrung scale, also called "cross-stringing". The strings are placed in a vertically overlapping slanted arrangement, with two heights of bridges on the soundboard, rather than just one. This permits larger, but not necessarily longer, strings to fit within the case of the piano. Overstringing was invented by Jean-Henri Pape during the 1820s, and first patented for use in grand pianos in the United States by Henry Steinway Jr. in 1859.

Duplex scaling: Treble strings of a 182 cm. grand piano. From lower left to upper right: dampers, main sounding length of strings, treble bridge, duplex string length, duplex bridge (long bar perpendicular to strings), hitchpins.

duplexes or aliquot scales. In 1872 Theodore Steinway patented a system to control different components of string vibrations by tuning their secondary parts in octave relationships with the sounding lengths. Similar systems developed by Bluthner (1872), as well as Taskin (1788), and Collard (1821) used more distinctly ringing undamped vibrations to modify tone.

Today's upright, grand, and concert grand pianos attained their present forms by the end of the 19th century. Improvements have been made in manufacturing processes, and many individual details of the instrument continue to receive attention.

Some early pianos had shapes and designs that are no longer in use.

The square piano had horizontal strings arranged diagonally across the rectangular case above the hammers and with the keyboard set in the long side, it is variously attributed to Silbermann and Frederici and was improved by Petzold and Babcock. Built in quantity through the 1890s (in the United States), Steinway's celebrated iron framed overstrung squares were more than two and a half times the size of Zumpe's wood framed instruments that were successful a century before, their overwhelming popularity was due to inexpensive construction and price, with performance and sonority frequently restricted by single actions and double stringing.

The tall vertically strung upright grand was arranged with the soundboard and bridges perpendicular to keys, and above them so that the strings did not extend to the floor. Diagonally strung Giraffe, pyramid and lyre pianos employed this principle in more evocatively shaped cases. The term was later revived by many manufacturers for advertising purposes.

The very tall cabinet piano introduced by Southwell in 1806 and built through the 1840s had strings arranged vertically on a continuous frame with bridges extended nearly to the floor, behind the keyboard and very large sticker action.

The short cottage upright or pianino with vertical stringing, credited to Robert Wornum about 1810 was built into the 20th century. They are informally called birdcage pianos because of their prominent damper mechanism. Pianinos were distinguished from the oblique, or diagonally strung upright made popular in France by Roller & Blanchet during the late 1820s.

The tiny overstrung spinet upright had a compact full iron frame and a so-called drop action arranged below the level of the keys. Spinet pianos were first manufactured in the mid-1930s. These smaller pianos are well-suited for people who live in smaller houses or apartments, and their lighter weight makes them easier to move. Spinet pianos, however, have their drawbacks. The drop-action and shorter keys make it harder for a pianist to have dynamic control while playing, and the shorter strings result in a less wide range of harmonics. A few piano technicians will not even service spinet pianos as their drop-action design makes them difficult to work on. At present, very few companies are making spinet pianos.

Piano history and musical performance

The huge changes in the evolution of the piano have somewhat vexing consequences for musical performance. The problem is that much of the most widely admired piano repertoire - for example, that of Haydn, Mozart, and Beethoven - was composed for a type of instrument that is rather different from the modern instruments on which this music is normally performed today. Even the music of the Romantics, including Chopin, Schumann, and Brahms, was written for pianos substantially different from ours. The interpretation of these works on modern pianos poses a variety of problems.

The modern piano

Types

Modern pianos come in two basic configurations and several sizes: the grand piano and the upright piano.

Grand pianos have the frame and strings placed horizontally, with the strings extending away from the keyboard. This makes the grand piano a large instrument, for which the ideal setting is a spacious room with high ceilings for proper resonance. There are several sizes of grand piano. Manufacturers and models vary, but a rough generalisation distinguishes the "concert grand", (between about 2.2 m to 3 m long) from the "boudoir grand" (about 1.7 m to 2.2 m) and the smaller "baby grand" (which may be shorter than it is wide). All else being equal, longer pianos have better sound and lower inharmonicity of the strings (so that the strings can be tuned closer to equal temperament in relation to the standard pitch with less stretching), so that full-size grands are almost always used for public concerts, whereas baby grands are often chosen for domestic use where space and cost are considerations.

Upright pianos, also called vertical pianos, are more compact because the frame and strings are placed vertically, extending in both directions from the keyboard and hammers. It is considered harder to produce a sensitive piano action when the hammers move horizontally, rather than upward against gravity as in a grand piano; however, the very best upright pianos now approach the level of grand pianos of the same size in tone quality and responsiveness. However, one feature of the grand piano action always makes it superior to the vertical piano. All grand pianos have a special repetition lever in the playing action that is absent in all verticals. This repetition lever, a separate one for every key, catches the hammer close to the strings as long as the key remains depressed. In this position, with the hammer resting on the lever, a pianist can play repeated notes, staccato, and trills with much more speed and control than they could on a vertical piano. The action design of a vertical prevents it from having a repetition lever. Because of this, piano manufacturers claim that a skilled piano player can play as many as 14 trill notes per second on grands but only 7 on uprights.

In 1863, Henri Fourneaux invented the player piano, a kind of piano which "plays itself" from a piano roll without the need for a pianist. Also in the 19th century, toy pianos began to be manufactured.

A relatively recent development is the prepared piano, which is simply a standard grand piano which has had objects placed inside it before a performance in order to alter its sound, or which has had its mechanism changed in some way.

Since the 1980s, digital pianos have been available, which use digital sampling technology to reproduce the sound of each piano note. The best digital pianos are sophisticated, with features including working pedals, weighted keys, multiple voices, and MIDI interfaces. However, with current technology, it remains difficult to duplicate a crucial aspect of acoustic pianos, namely that when the damper pedal (see below) is depressed, the strings not struck vibrate sympathetically when other strings are struck. Since this sympathetic vibration is considered central to a beautiful piano tone, in many experts' estimation digital pianos still do not compete with the best acoustic pianos in tone quality. Progress is being made in this area by including physical models of sympathetic vibration in the synthesis software.

Keyboard

This arrangement was inherited from the harpsichord without change, with the trivial exception of the colour scheme (white for notes in the C major scale and black for other notes) which became standard for pianos in the late 18th century.

Almost every modern piano has 88 keys (seven octaves plus a minor third, from A0 to C8). Many older pianos only have 85 keys (seven octaves from A0 to A7), while some manufacturers extend the range further in one or both directions. The most notable example of an extended range can be found on Bosendorfer pianos, two models which extend the normal range downwards to F0, with one other model going as far as a bottom C0, making a full eight octave range. Sometimes, these extra keys are hidden under a small hinged lid, which can be flipped down to cover the keys and avoid visual disorientation in a pianist unfamiliar with the extended keyboard; on others, the colours of the extra white keys are reversed (black instead of white). The extra keys are added primarily for increased resonance; that is, they vibrate sympathetically with other strings whenever the damper pedal is depressed and thus give a fuller tone. Only a very small number of works composed for piano actually use these notes. More recently, the Stuart and Sons company has also manufactured extended-range pianos. On their instruments, the range is extended both down the bass to F0 and up the treble to F8 for a full eight octaves. The extra keys are the same as the other keys in appearance.

Pedals

Pianos have had pedals, or some close equivalent, since the earliest days. (In the 18th century, some pianos used levers pressed upward by the player's knee instead of pedals.) The three pedals that have become more or less standard on the modern piano are the following.

The damper pedal (also called the sustaining pedal or loud pedal) is often simply called "the pedal," since it is the most frequently used. It is placed as the rightmost pedal in the group. Every string on the piano, except the top two octaves, is equipped with a damper, which is a padded device that prevents the string from vibrating. The damper is raised off the string whenever the key for that note is pressed. When the damper pedal is pressed, all the dampers on the piano are lifted at once, so that every string can vibrate. This serves two purposes. First, it assists the pianist in producing a legato (playing smoothly connected notes) in passages where no fingering is available to make this otherwise possible. Second, raising the damper pedal causes all the strings to vibrate sympathetically with whichever notes are being played, which greatly enriches the piano's tone.

Sensitive pedaling is one of the techniques a pianist must master, since piano music from Chopin onwards tends to benefit from extensive use of the sustaining pedal, both as a means of achieving a singing tone and as an aid to legato. In contrast, the sustaining pedal was used only sparingly by the composers of the 18th century, including Haydn, Mozart and in early works by Beethoven; in that era, pedalling was considered primarily as a special coloristic effect.

The soft pedal or "una corda" pedal is placed leftmost in the row of pedals. On a grand piano, this pedal shifts the whole action including the keyboard slightly to the right, so that hammers that normally strike all three of the strings for a note strike only two of them. This softens the note and also modifies its tone quality. For notation of the soft pedal in printed music, see Italian musical terms.

The soft pedal was invented by Cristofori and thus appeared on the very earliest pianos. In the 18th and early 19th centuries, the soft pedal was more effective than today, since it was possible at that time to use it to strike three, two or even just one string per note-this is the origin of the name "una corda", Italian for "one string". In modern pianos, the strings are spaced too closely to permit a true "una corda" effect - if shifted far enough to strike just one string on one note, the hammers would also hit the string of the next note.

On upright pianos, the soft pedal operates a mechanism which moves the hammers' resting position closer to the strings. Since the hammers have less distance to travel this reduces the speed at which they hit the strings, and hence the volume is reduced, but this does not change tone quality in the way the "una corda" pedal does on a grand piano.

Digital pianos often use this pedal to alter the sound to that of another instrument such as the organ, guitar, or harmonica. Pitch bends, leslie speaker on/off, vibrato modulation, etc. increase the already-great versatility of such instruments.

The sostenuto pedal or "middle pedal" keeps raised any damper that was raised at the moment the pedal is depressed. This makes it possible to sustain some notes (by depressing the sostenuto pedal before notes to be sustained are released) while the player's hands are free to play other notes. This can be useful for musical passages with pedal points and other otherwise tricky or impossible situations. The sostenuto pedal was the last of the three pedals to be added to the standard piano, and to this day many pianos are not equipped with a sostenuto pedal. (Almost all modern grand pianos have a sostenuto pedal, while most upright pianos do not.) A number of twentieth-century works specifically call for the use of this pedal, for example Olivier Messiaen's Catalogue d'oiseaux.

Some upright pianos have a practice pedal or celeste pedal in place of the sostenuto. This pedal, which can usually be locked in place by depressing it and pushing it to one side, drops a strip of felt between the hammers and the keys so that all the notes are greatly muted - a handy feature for those who wish to practice in domestic surroundings without disturbing the neighbours. The practice pedal is rarely used in performance. Other uprights have a bass sustain as a middle pedal. It works like the damper pedal, but only lifts the dampers for the lowest notes.

The rare transposing piano, of which Irving Berlin possessed an example, uses the middle pedal as a clutch which disengages the keyboard from the mechanism, enabling the keyboard to be moved to left or right with a lever. The entire action of the piano is thus shifted to allow the pianist to play music written in one key so that it sounds in a different key.

Materials

Many parts of a piano are made of materials selected for extreme sturdiness. In quality pianos, the outer rim of the piano is made of a hardwood, normally maple or beech. According to Harold A. Conklin, the purpose of a sturdy rim is so that "the vibrational energy will stay as much as possible in the soundboard instead of dissipating uselessly in the case parts, which are inefficient radiators of sound." The rim is normally made by laminating flexible strips of hardwood to the desired shape, a system that was developed by Theodore Steinway in 1880.

The thick wooden braces at the bottom (grands) or back (uprights) of the piano are not as acoustically important as the rim, and are often made of a softwood, even in top-quality pianos, in order to save weight.

The pinblock, which holds the tuning pins in place, is another area of the piano where toughness is important. It is made of hardwood, and generally is laminated (built of multiple layers) for additional strength and gripping power.

Piano strings (also called piano wire), which must endure years of extreme tension and hard blows, are made of high quality steel. They are manufactured to vary as little as possible in diameter, since all deviations from uniformity introduce tonal distortion. The bass strings of a piano are made of a steel core wrapped with copper wire, to increase their flexibility.

The plate, or metal frame, of a piano is usually made of cast iron. It is advantageous for the plate to be quite massive. Since the strings are attached to the plate at one end, any vibrations transmitted to the plate will result in loss of energy to the desired (efficient) channel of sound transmission, namely the bridge and the soundboard. Some manufacturers now use cast steel in their plates, for greater strength. The casting of the plate is a delicate art, since the dimensions are crucial and the iron shrinks by about one percent during cooling. The inclusion in a piano of an extremely large piece of metal is potentially an aesthetic handicap. Piano makers overcome this handicap by polishing, painting, and decorating the plate; often plates include the manufacturer's ornamental medallion and can be strikingly attractive.

The numerous grand parts and upright parts of a piano action are generally hardwood (e.g. maple, beech. hornbeam). Since World War II, plastics have become available. Early plastics were incorporated into some pianos in the late 1940s and 1950s, but proved disastrous because they crystallized and lost their strength after only a few decades of use. The Steinway firm once incorporated Teflon, a synthetic material developed by DuPont, for some grand action parts in place of cloth, but ultimately abandoned the experiment due to an inherent "clicking" which invariably developed over time. More recently, the Kawai firm has built pianos with action parts made of more modern and effective plastics such as carbon fiber; these parts have held up better and have generally received the respect of piano technicians.

View from below of a 182-cm grand piano. In order of distance from viewer: softwood braces, tapered soundboard ribs, soundboard. The metal rod at lower right is a humidity control device.

The part of the piano where materials probably matter more than anywhere else is the soundboard. In quality pianos this is made of solid spruce (that is, spruce boards glued together at their edges). Spruce is chosen for its high ratio of strength to weight. The best piano makers use close-grained, quarter-sawn, defect-free spruce, and make sure that it has been carefully dried over a long period of time before making it into soundboards. In cheap pianos, the soundboard is often made of plywood.

Piano keys are generally made of spruce or basswood, for lightness. Spruce is normally used in high-quality pianos. Traditionally, the black keys were made from ebony and the white keys were covered with strips of ivory, but since ivory-yielding species are now endangered and protected by treaty, plastics are now almost exclusively used. Legal ivory can still be obtained in limited quantities. At one time the Yamaha firm innovated a plastic called "Ivorine" or "Ivorite", since imitated by other makers, that mimics the look and feel of ivory.

The requirement of structural strength, fulfilled with stout hardwood and thick metal, makes a piano heavy; even a small upright can weigh 136 kg (300 lb), and the Steinway concert grand (Model D) weighs 480 kg (990 lb). The largest piano built, the Fazioli F308, weighs 691 kg (1520 lb).

Care and maintenance

Pianos are regularly tuned to keep them up to pitch and produce a pleasing sound; by convention they are tuned to the internationally recognised standard concert pitch of A = 440 Hz.

The hammers of pianos are voiced to compensate for gradual hardening. Top-quality but aged pianos can be restored or reconditioned, by replacing a great number of their parts to produce an instrument closely similar to a new one.

The role of the piano

The piano is a crucial instrument in Western classical music, jazz, film, television and electronic game music, and most other complex western musical genres. A large number of composers being proficient pianists, the piano is often used as a tool for composition.

Pianos were, and are, popular instruments for private household ownership, especially among the middle and upper classes. Hence pianos have gained a place in the popular consciousness, and are sometimes referred to by nicknames, including: "the ivories", "the joanna", "the eighty -eight", and "the black(s) and white(s)." Playing the piano is sometimes referred to as "tickling the ivories".

References

Most of the information in this article can be found in the following published works:

The authoritative New Grove Dictionary of Music and Musicians (available online by subscription), contains a great wealth of information. Main article: "Pianoforte".
The Encyclopedia Britannica (available online by subscription) also includes much information on the piano. In the 1988 edition, the primary article can be found in "Musical Instruments".
The Piano Book by Larry Fine (4th ed. Jamaica Plain, Massachusetts: Brookside Press, 2001; ISBN 1-929145-01-2) gives the basics of how pianos work, and a thorough evaluative survey of current pianos and their manufacturers. It also includes advice on buying and owning pianos.
Giraffes, black dragons, and other pianos : a technological history from Cristofori to the modern concert grand by Edwin M. Good (1982, Stanford, Calif. : Stanford University Press) is a standard reference on the history of the piano.
The Early Pianoforte by Stewart Pollens (1995, Cambridge: Cambridge University Press) is an authoritative work covering the ancestry of the piano, its invention by Cristofori, and the early stages of its subsequent evolution.

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