Set-off button [escapement button, set-off screw]. A regulating button that controls the moment (the ‘set-off’) at which a jack or hopper is made to disengage from the hammer when a key is depressed.

Shaping. Process of filing hammers into a proper shape to reduce the best and most consistent tone.

Sharp key. Accidental raised keys traditionally made of ebony but today more likely to be made of black molded plastic or stained hardwood.

Short octave. A term to denote the lowering of the pitch of some bass notes to extend the compass downwards. This was to meet the requirements of a specific piece of music and was not practiced after the early 19th century.

Side bearing. The force of the strings as they zigzag through the bridge pins. Assures energy transmission from strings to bridge.

Single action. See ENGLISH SINGLE ACTION.

Single close fallboard. Key-cover pulls forward and down in one smooth movement.

Slab-type cabinet keyboards. Portable rectangular electronic instruments typically about 3 to 4 inches high and about a foot deep. The length varies with the number of keys offered, from as small as 2 feet long to as much as 4 feet in length.

Soft pedal. See UNA CORDA.

Sostenente piano. A term used in connection with attempts to produce a strung keyboard instrument that could sustain sound. In the 18th and 19th centuries a number of devices were invented, often taking the form of attachment to the action. They included continuous bows, bellows through which jets of air were driven against the strings, vibrating rods, free reeds and tremolo mechanisms. The modern sostenente piano is the ‘electronic’ piano.

Sostenuto pedal. Middle pedal or performance grands that captures and sustains notes selected before pedal is depressed. Found on a very few upscale uprights.

Soundboard. A wooden wood made of spurce that vibrates at the same frequency of the strings and so amplifies their volume.

Spine. The long side of a grand piano case, opposite to the bentside.

Spinet. A term used in the USA during the 1930s to describe a miniature upright piano.

Spinet piano. An upright piano measuring up to 39″ high.

Square piano. A rectangular horizontal piano that derive its shape from the clavichord.

Square pianoforte. An early piano that retained the rectangular shape of the clavichord.

Stencil piano. Traditionally, the term for a piano that is made as a house brand or a private label instrument. The brand name on the front of the piano is not the same as that on the front of the factory. For example, Company XYZ wants to carry a private label so it contracts with a manufacturer to make pianos that say Company XYZ on the front. Several Chinese manufacturers make private label pianos. Frequently stencil (private label) names are contrived to sound like a famous maker like Steinway & Sons. Other stencils are contrived to sound German with the eye toward deception as to origin and hence price. Not all stencil pianos are meant to deceive buyers, however. Some manufacturers have contracted with another manufacturer to build an instrument with design and materials specifications that are different from the building factory’s regular models. These exceptions do not fit the traditional definitions of a true stencil.

Sticker. A rigid rod, usually wooden, which exerts a pushing action against either the hammer or damper in a piano mechanism.

Sticker action. The action developed initially by Southwell for an upright version of a squarepiano and later applied to the English upright cabinet piano. A sticker, sometimes of great length, is used to communicate the motion of the hammer to the jack at the top of the case.

Stock keeping unit (SKU). A system for identifying and tracking individual discrete models and finishes.

Stop. A hand control, knee lever or pedal that mechanically modifies the piano’s timbre.

Stossmechanik. The German term for an action where the hammer is mounted on a separate rail and not on the key.

Strahlenklavier (Ger.: ‘beamlike piano’). A redesigned piano, made by Bechstein c1870, which devided the keyboard into two arcs to allow for the range of each arm. The design was faulty, since it resulted in the player constantly having his elbows pressed into the body.

Studio piano. An upright piano measuring 44″ to 46″ high.

Strung back. The part of the piano responsible for producing and amplifying the sound, as well as supporting the high amount of tension produced by the strings.

Support. See WIPPEN.

Sustain (loud) pedal. Right pedal that lifts the entire damper assembly to sustain the tone.

Sympathetic strings. Unstruck strings that are added so as to increase sonority. See ALIQUOT SCALING; DUPLEX SCALE.

Tangent piano (Ger. Tangentenflugel). A keyboard instrument, said to have been invented by Spath c1751, in which the strings are struck by freely moving slips of wood resembling harpsichord jacks. Spath’s design was anticipated by Schroter in 1739 and possibly by Marius in 1716.

Tape-check. See BRIDLE.

Telio-chordon. A microtonal grand piano invented by Charles Clagget in 1788. The octave was divided into 39 intervals and each key, with the help of pedals, operated three notes.

Touche (Fr.). KEY.

Touch training. A term given to the aspects of beginning piano lessons that focus on the tacticle issues of learning and playing the keys and learning to play the levels of dynamics (loud and softs).

Transposing keyboard. A keyboard that can be shifted laterally, usually by means of a lever, enabling a performer to play music in a different key from that in which it is written. The keys, when shifted, strike strings at a chosen interval above or below the norm.

Tuning. Precise adjustment of the string tensions to proper pitches and consistencies by turning the tuning pins, using a tuning hammer. This is done aurally or in conjunction with an electronic tuning device (ETD) that shows graphic representations of pitch. These ETDs may also store tuning properties of dozens of specific pianos for future reference.

Tuning fork. An acoustic resonator in the form of a two-pronged fork with the prongs (tines) formed from a U-shaped bar of elastic metal (usually steel).

Tuning hammer or lever. A device with a handle that holds a socket-wrench type tip on it that fits over the tuning pins. Pitch is adjusted by turning and setting the pins; movements are minute and hammer technique is critical.

Tuning pins. Steel pins approximately 2 and one-half inches long and one-fourth inch in diameter found near the top of a vertical piano and toward the front of grand pianos. Piano strings are wound around the tuning pins and the pins are driven into the tuning block. The tuning pins hold tension on the strings. This tension is adjusted up or down during the tuning process.

Turkish music. See JANISSARY STOP.