According to Wikipedia

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. This is partly because the strings will be tuned closer to equal temperament in relation to the standard pitch with less stretching (See: Piano tuning). Full-size grands are usually 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 seven on uprights. For recent advances, see Innovations in the piano.

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 as well as the unique instrument-specific mathematical non-linearity of partials on any given unison. 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

For the arrangement of the keys on a piano keyboard, see Musical 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 Bösendorfer pianos, one model which extends 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 from the associated strings; 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 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 pianos were manufactured with only two strings per note, just one string per note would be therefore struck — this is the origin of the name "una corda", Italian for "one string". In modern pianos, there are three strings per hammer and 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 hit the string of the next note.

On many 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. This pedal is often unused in modern music.

Many uprights and baby grands have a bass sustain in place of the sostenuto pedal, which lifts all the dampers in the bass. It works like the damper pedal, but only affects the lowest notes.

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 strings 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.

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.

See also: Pedal piano