Player Piano

Background

The player piano begins as a standard, or non-player, acoustic piano. It contains a keyboard, and, when the keys are struck, felt hammers strike tuned metal strings to create musical tones. The intricate collection of felt hammers and connecting parts is called the "piano action." The piano action can be manipulated with the musician's fingers, or, if the piano is equipped with a player system, the piano action can be operated by the "player action" of the player piano itself.

The traditional, roll-operated player piano has a pneumatic (air-driven) player action that operates the piano action. Associated with each piano key is a striker, which resembles a miniature bellows. As each striker is pneumatically collapsed, its corresponding key is pushed to play. The full set of strikers comprises the player action. The player action "reads music" by detecting coded perforations in paper rolls. This detection is done by a system of pneumatic tubes and valves, and, as the perforations are noted, the pneumatic system tells the strikers when to collapse. An electric vacuum motor or pedals that are pumped by foot supply the pneumatic power.

The traditional roll-player piano has several disadvantages. The player action must be built in the piano during assembly; it can't be added later. Also, the pneumatic strikers push their keys at one dynamic level only, so the notes of the music are heard, but without soft or loud variations.

The modern player piano has a player action that uses electronically-driven solenoids as strikers. A solenoid is a tubular coil that acts like a magnet when traversed by an electric current. The solenoids respond to signals from a Musical Instrument Digital Interface or MIDI, which is the universal electronic language spoken by keyboards, music synthesizers, and other electronic instruments. The MIDI is considerably more sophisticated than the roll-player system, and plays both the notes and dynamics as recorded by the musician. Libraries of recorded music are stored on floppy or compact disks so the piano can play virtually any piece of music. If equipped with appropriate software and electronics, the player piano can also play recorded vocalists, instruments, or a full symphony orchestra. Thanks to the common MIDI language, it can also be linked to sequencers, drum machines, and synthesizers as well as computers.

History

When King Henry VIII of England died in 1547, his musical instruments were inventoried and, among them, was "an instrument that goethe with a whele without playing upon." Early player pianos were known to have been built by piano builder Samuel Bidermann of Augsburg, Germany. He equipped three spinets (small, upright pianos) with pinned barrels similar to those in music boxes during his lifetime from 1540 to 1622.

Interest in inventing a self-playing piano resurfaced in the late 1890s. Several different mechanisms were developed and sold, but the paper rolls were not interchangeable. Melville Clark, an inventor and piano designer, developed an 88-note, standardized roll size for the player industry, and built his Apollo player piano to this standard in 1901. By 1908, other manufacturers had adopted his standard. The paper rolls were punched by duplicating machines called perforators from a master roll used as a pattern. The master rolls were tediously hand-punched by skilled workers directly from sheet music. To avoid this production difficulty, Clark invented the "marking piano" in 1912. His marking piano punched the master roll data as the musician performed a piece of music. The marking piano was used from 1912 to 1931.

Historic performances by artists of the day were preserved in live recordings, and the marking piano made the Roaring Twenties the heyday of the player piano until the popularity of the phonograph and radio surpassed it. In 1926, its peak sales year, over 10 million piano rolls were sold. The marking piano was retired in 1931, restored in 1971 to record the performances of other outstanding artists, and designated a National Historic Mechanical Engineering Landmark in 1992. Following all-time low sales in the 1950s, roll-player pianos experienced a revival in the 1970s, and traditional player pianos and paper rolls are still manufactured and sold.

In the 1920s, experiments began with electric or electromagnetic devices in place of the piano soundboard. Electronic pianos, keyboards, and music synthesizers use electronic circuits or tuned metal pieces instead of strings to produce sound. Some generate sounds approaching those of a conventional piano, but they are most valued for producing effects that are electronically altered from the acoustic piano voice. Electronic applications began to merge with the acoustic piano in the 1970s; acoustic pianos (as opposed to electronic pianos) were equipped with various components such as digital cassette drives or computers to enable the acoustic piano to be played using electronic "brains" and power. Several major manufacturers now produce disc-driven player pianos, and systems and software are sold in kits to convert acoustic pianos to players. The instrument that has been idle since grade-school piano lessons can thus be converted to an entertainment center. The remainder of this article will focus on the manufacture of the disc-driven piano.

Raw Materials

Essentially no raw materials are used directly in the manufacture of disc-driven player pianos. Manufacturers provide specifications to vendors and then purchase required parts from them. These parts may include factory-produced acoustic pianos in which the player systems are installed.

Design

Engineers design the player piano system and develop new products. The manufacturer's legal staff, meanwhile, performs a thorough patent search so that new approaches do not infringe on existing patents, and the firm's own original concepts can be patented promptly. Prototypes are hand-assembled, tested, and evaluated for marketability and feasibility of construction. The engineers provide design details and specifications for every component of the product, including electrical, electronic, and mechanical parts; tooling and special machining or assembly; and requirements for operation, installation, testing, maintenance, and repair. Because few parts may be made on site, the search for parts or suppliers capable of making them may be worldwide.

Software engineers must also provide the programming so that computer chips can convert notes and data representing musical expressions into electronic signals that drive the solenoids. More than 1,000 pages of computer code may be required for this complicated communication.

To appeal to a broad market, the player piano must be able to play a wide range of music, so a large music library in software form has also been developed and updated. The "codes" from traditional player piano rolls don't translate easily to the MIDI language, but actual performances are ideally suited to the digital system because they convey interpretive elements. Manufacturers maintain their own recording studios and recruit name performers to play their piano stylings. Music editors review the recorded performances, correct any errors or inconsistencies, or modify performances in accordance with musical scores, as appropriate. The legal staff secures contracts, releases, and licenses to the music and performances.

The Manufacturing
Process

Player subassembly

• 1 The player subassembly is the player action that consists of 88 solenoids and plungers that are computer-activated to move the keys. It is made of preexisting parts that are put together along an assembly line using a combination of hand-assembly and automated processes. The electronics, including the power supply, control box, key activation devices, and interconnections, are controlled by the components on a printed circuit board. Circuit boards in panel form (multiple boards of the same kind made on one large panel and separated after components are inserted) are used to facilitate automated assembly because components can be added easily. Components of a single kind are supplied in long rolls that are fed through an automated sequencer. The sequencer checks to make sure each part is correct, then organizes an array of parts into the proper sequence for insertion in the circuit board. Some parts are formed, shaped, and inserted in the board by an automated dip inserter that can also check the appropriateness of the part. Other parts are added by hand.
• 2 The parts are soldered in place by passing the circuit board through a wave soldering machine. It washes the board with flux to remove contaminants, heats the board and components by infrared heat to reduce thermal shock as the board is soldered, then passes the underside of the board over a wave of molten solder. The solder flows up each component and board perforation by capillary action to the upper surface of the board. It cools and hardens, fixing the components in place.
• 3 The completed circuit boards are installed in control boxes and tested as a quality assurance step. Software is loaded and the control boxes are activated over a two-day-long test period, or "burn-in" process, that simulates the actual working of the player system. Any failures during that time are detected and corrected.
• 4 On another part of the player subassembly line, the solenoids and plungers are made and installed on a rail or support. Magnetic wire is wrapped by machine on the solenoid bases and sealed in place. Wire connections are also attached to each solenoid, and the plunger assemblies are paired with solenoids. The solenoids and plungers are assembled on aluminum rails. Depending on the manufacturer, the solenoid/plungers vary in configuration, and the rail may be one piece or several sections. Rail mounting brackets will be used later to mount the solenoids under the piano keyboard. A similar assembly is made to activate the piano pedals.

Recording strip

• 5 The player piano can also record music played on the piano if a recording strip is installed; this allows students or performers to play back their work and aids composers in creating and revising their compositions. The recording strip consists of a mounting rail and tiny electronic film switches that are cased in plastic. There is one switch or finger per key; and the recording strip is sensitive to the key or keys that are struck, the duration they are depressed, and the velocity or intensity (soft or loud) per key strike. The recording strip is linked electronically to the piano's computer, where signals are processed into MIDI messages. This data can be stored by analog media like a cassette player or VCR, or directed to a floppy disk drive. It can be played back by the piano or other MIDI-compatible instrument.

Disc-player

• 6 The disc-player and other devices are connected to the player piano via the control box. It may be a floppy disk drive, compact disc (CD) player, or both; player pianos can also be attached to VCRs in combination with televisions or computer monitors so lyrics can be synchronized for sing-alongs or other programmed entertainment. Most manufacturers purchase these components and remote controls for them from outside suppliers.

Accompaniment and speakers

• 7 As another added feature, the piano can play along with all manner of recorded accompaniments including vocals, other individual instruments, or an orchestra. The "soundboxes" for these additions are electronic speakers that can be furnished as accessories to the piano and that are supplied by vendors. Software is added to supply the other sounds via the MIDI system.

Piano installation

• 8 On another assembly line, the player subassembly and recording strip are installed in a piano. The pianos are supplied by the manufacturer's own piano division or an out-side vendor. A slot is cut in the wood under the piano keyboard, but the structural integrity of the piano is not affected. The solenoid rail or set of rails is mounted under the piano so that the plungers are under the tails of the keys. The recording strip is similarly installed. The solenoid links with the pedals are also connected, the control box is mounted under the keyboard, and the power supply is mounted to the underside of the piano. The piano action must be adjusted at this point. The keys rest on felt pads that compress with use, so the pianos are programmed to play overnight in another burn-in process. After a 12-hour "concert," the felt has compressed. Then the components are checked to see that they have worked properly, and the piano action is adjusted to suit the felt compression. The pianos are packed and shipped when installation is complete.

Kit assembly

• 9 Some manufacturers provide their disc-driven systems in kits that can be used to retrofit standard pianos to players. As the completed subassemblies, control boxes and power supplies, and recording strips come off the assembly lines, they are packaged and stored. Kits are then packed with these units as well as disc-players and accessories. The kits are shipped to installers who have been specially trained to install the particular manufacturer's system. Installation typically takes up to two days, including an overnight burn-in session after which the piano action is adjusted and component workings are checked as they are in the factory.

Quality Control

Quality control is essential in every production step. As parts are received from vendors around the world, they are checked for compliance with specifications and other engineering requirements. Along the player subassembly line, workers perform quality checks as part of their responsibility. For example, as circuit boards emerge from the wave soldering machine, the operator inspects the board to see that parts have been soldered in place, no bridging of solder has occurred from one component to another, and the board itself has not warped or cracked. The operator also monitors the machine for temperature of the solder and overall operation of the machine. Electronic assemblies must also meet the requirements of Underwriters' Laboratories (UL). UL representatives visit the manufacturers frequently and randomly to check for compliance with their materials, operations, and safety codes. Other quality checks, such as the burn-ins of control boxes and piano actions, are integrated into the manufacturing process, as described.

The Future

Acoustic pianos are instruments long-favored by listeners, and their future is assured by the disc-driven player piano which provides the sounds and entertainment benefits without requiring the listener to become a virtuoso. Disc-driven player pianos have initiated substantial increases in the sales of pianos, and are seen as the growth sector of the industry. In the discdriven player piano's future, manufacturers are striving to reproduce performance nuances. Continued merging of technologies also seems likely as professional recording studios are used to input music and as methods are found of linking the player piano to other electronic media.