An electrically amplified keyboard instrument capable of producing piano-like sounds; its sound-generating system may, but need not, consist of strings (for classification, see Electronic instruments, §I, 2(i)(a)). The range of such instruments includes modified pianos and instruments that bear a close resemblance to a normal upright or grand piano and its mechanism. Fully electronic keyboard instruments, in which the sounds are generated by electronic oscillators, produce similar sounds – usually with additional timbres such as harpsichord, vibraphone and clavinet (one of Hohner's early electric piano-like keyboards) – and are classified as electronic pianos; digital pianos were introduced in the early 1980s, originally based on digital synthesis, from around 1986 primarily featuring sampled piano sounds. Their increasingly realistic timbres and comparative cheapness of manufacture resulted in the production of electric pianos ceasing around 1985, although many ‘classical’ instruments are still played by rock musicians. Some companies have also added MIDI to acoustic pianos, equipping them with optical sensors that respond to key, hammer or string movements.
The first electric pianos appeared on both sides of the Atlantic around 1930. Three of the pioneers, Benjamin F. Miessner, of Millburn, New Jersey, and Walther Nernst and Oskar Vierling of Berlin, achieved considerable sophistication in their efforts. Miessner's patent for an electric piano (based on his Electronic Piano, 1930–31), without soundboard and using electrostatic transducers for the amplification system, formed the basis of several instruments manufactured in North America between 1935 and 1939. Nernst and Vierling were members of the team that developed the Neo-Bechstein-Flügel (1931; fig.1), and Vierling alone designed the Elektrochord (1932).
The adaptation of the acoustic instrument to the electric version involved considerable changes. Double or triple strings were often dispensed with and thinner wire was used. Since the vibrations of the strings directly affected electromagnetic pickups or electrostatic transducers, no energy-absorbing soundboard was necessary; thus the strings resonated with an organ-like timbre for up to a minute, unless, as in the Neo-Bechstein, additional dampers were brought into operation to obtain a conventional duration of sustain. In the Neo-Bechstein the strings were grouped in fives, each group converging towards a pickup (for the full range of 88 chromatic notes, 18 pickups were employed); the keyboard-hammer-damper action was similar to that of the conventional piano but redesigned to accommodate the much lighter touch necessary for this instrument. The basic construction of an electric piano was much lighter than that of the ordinary grand piano, but this was offset by the weight of the pickups and often of an amplifier and even a built-in loudspeaker.
As with other electric instruments, designers of electric pianos concentrated on the loudspeaker sound and deliberately reduced the loudness of the purely acoustic sounds produced by the mechanism. The impact of the hammers on the strings itself produced little tone without a soundboard, but the volume could be controlled with the left pedal, or an additional swell pedal, which directly influenced the degree of amplification given to the signals from the pickups. Thus a sustaining or even swelling of notes could be achieved, the greatest possible deviation from the natural sound of the acoustic instrument. The right pedal retained its normal function of raising the dampers. The amplification system also made possible alterations in the timbre of the sound by means of pickups positioned at different points along the strings, or by filtering or amplifying the harmonics electronically.
A few electric pianos were constructed in the 1930s that did not use a piano-like mechanism. In the Variachord (1937) the strings were activated by electromagnets; the Clavier (1934) of Lloyd Loar and Selmer's Pianotron (1938) used plucked reeds as the sound source. Most modern electric pianos also abandoned conventional piano action and with it the form of the upright or grand piano, appearing as portable keyboards on legs, similar to many small electronic organs. The tone-producing elements were often steel rods (electric piano by Harold Rhodes, 1965) or reeds (Wurlitzer electric piano, 1954) which, when struck with felt-covered wooden hammers (or plucked, as in the Hohner Pianet, 1962), vibrate in a polarized electrical field (fig.2). Some are designed to simulate as closely as possible the sound of a conventional piano, while others have tone-modifying devices that also imitate the harpsichord, clavichord or honky-tonk piano. Most postwar electric pianos incorporate electromagnetic or piezoelectric crystal pickups; electrostatic methods were rarely used.
Finally, one should note the practice of electrically amplifying an acoustic grand piano. Usually this is done merely to create a louder sound, for example, to balance other amplified instruments. In some compositions, however, microphones are used to pick up sounds from a piano for transformation by means of other devices, as in Cage's Electronic Music for Piano (1964) and Stockhausen's Mantra (1970).
GroveA (R. Orton)
GroveJ (‘Piano’, §6; L. Koch)
O. Vierling: Das elektroakustische Klavier (Berlin, 1936)
B.F. Miessner: ‘The Electronic Piano’, Music Teachers National Association: Proceedings, xxxii (1937), 259–72
W. Meyer-Eppler: Elektrische Klangerzeugung: elektronische Musik und synthetische Sprache (Bonn, 1949), 95–8
T.L. Rhea: The Evolution of Electronic Musical Instruments in the United States (diss., George Peabody College, 1972), 98–120; rev. in Contemporary Keyboard, iii/12–iv/5 (1977–8); repr. in The Art of Electronic Music, ed. T. Darter and G. Armbruster (New York, 1984), 16–23
J.H.M. Goddijn: Groot elektronisch orgelboek (Deventer, 1975), 224–32
B. Carson: ‘A Parade of Exotic Electric Pianos and Fellow Travellers’, Keyboard, xix/12 (1993), 141–58
D. Crombie: Piano: Evolution, Design and Performance (London, 1995), 74–9
RICHARD ORTON/HUGH DAVIES