Transposing keyboard.

One that enables the performer readily to play music in a different key from that in which it is written, generally for the purpose of enabling the music to sound at a different pitch (usually to accommodate a keyboard accompaniment to the fixed or preferred pitch of other instruments or singers) or to permit the playing of music in a ‘difficult’ key while using the fingering of an ‘easy’ key. There are two principal ways in which this may be accomplished. In one, the keyboard simply slides sideways relative to the jacks, hammers, stickers, strings etc. of the instrument of which it is a part. In the other method, there are two keyboards which are displaced from each other by a certain fixed interval.

The latter method is known principally from the standard two-manual harpsichords made by the Ruckers family in the late 16th-century and the first half of the 17th. In these, the upper keyboard sounds at normal pitch, while the lower keyboard, which plays the same strings as the upper keyboard, is positioned so that it sounds a fourth lower. The lower-manual f''' key, for example, is aligned with the upper-manual c''' key and acts on the same strings. O'Brien (1990) has suggested that a harpsichord by Joannes Ruckers, 1612 (in Fenton House, Hampstead), might originally have had a different arrangement, with the two keyboards a whole tone apart. Although there is no known evidence of organs with transposing keyboards like those in Ruckers harpsichords, there are occasional accounts of organs which included separate keyboards with their own pipework at a different pitch from the main instrument. In 1513 a second small organ, tuned a whole tone higher, was appended to the main organ in the church of St Jacobi, Innsbruck; the organ in the Hohenstiftskirche, Halberstadt, made by Heinrich Herbst in 1718, had two divisions with separate keyboards placed to the side, one tuned to ‘Chorton’ (choir pitch), presumably about a semitone below modern pitch), the other at ‘Cammerton’ (chamber pitch), presumably two or three semitones lower. Somewhat more frequently, in Germany during the 17th and 18th centuries, organs tuned to choir pitch would include, on one of the regular manuals, one or more stops at chamber pitch.

Transposing instruments with shifting keyboards have generally been more common than those with fixed keyboards. The earliest surviving examples include a harpsichord by Hans Müller of Leipzig (1537; Museo degli Srtumenti Musicali, Rome; for illustration see Harpsichord§2 (ii), fig.4) and a chamber organ by Michael Strobel (1559; Schloss Churburg, Sluderno, Italy). In both instruments the keyboard can be shifted by a whole tone, a transposition that Arnolt Schlick (Spiegel der Orgelmacher und Organisten, 1511) stated was particularly useful on the organ and which, he said, was possible on two instruments that he knew.

The utility of transposing keyboards was limited when unequal temperaments were prevalent. The Strobel organ, for example, is tuned in 1/4-comma mean-tone temperament, and when the keyboard is shifted to the right from its ‘home’ position the pattern of usable keys is also shifted. Thus, for example, the A and C keys play a pure third in the lower position of the keyboard but when shifted up they play pipes tuned in the home position to B and E, a dissonant diminished fourth. The problem was less severe in harpsichords, in which the tuning could easily be adjusted. Even so, the Ruckers provided doubled strings for the note which on the upper keyboard is played by the E key and on the lower keyboard by the G key, so that the former could be tuned pure to the upper-manual G key and the latter pure to the lower-manual E key. Otherwise, the lower-manual interval E–G would sound a diminished fourth, i.e., the interval played by the upper-manual B and E keys. Other problems are inherent in transposing keyboards with short octave tunings in the bass. In the Strobel organ, the pipes follow the standard C/E short-octave arrangement for the keyboard in the lower position, but this is disrupted when the keyboard is shifted upwards. In Ruckers harpsichords the strings follow the short-octave arrangement of the lower-manual keys, and the rear portions of three of the bass key levers in upper manual are cranked to the left to reach the appropriate strings (see illustration). Eventually, both of these problems were obviated when equal (or nearly equal) temperaments were used and when keyboards with chromatic bass compasses were made.

During the 17th and 18th centuries instruments with shifting keyboards were made occasionally, although they never became very common. Extant examples include an early 18th-century Thuringian harpsichord (in the Bachhaus, Eisenach) with a keyboard shifting over the interval of a minor third, presumably from deep chamber pitch (about a whole tone below modern pitch) to choir pitch, and two grand pianos made in the 1740s by Gottfried Silbermann, with keyboards shifting a semitone. Burney (1771) described two transposing instruments that he saw in 1770: a square piano, made in Berlin, in which, ‘by drawing out the keys the hammers are transferred to different strings’, and a harpsichord with a shifting keyboard made in Spain for Farinelli. A ‘false keyboard’ that could be installed over the functional key levers of an instrument was patented in Great Britain in 1801 by Edward Ryley with the express purpose of permitting ‘any piece of music wrote in the natural key of C … [to be] transposed throughout all the keys of music without the aid of flats or sharps’ and making possible ‘a new mode of playing, which requires the aid of one major and one minor key’. A surviving square piano made by Broadwood in 1808 (now in a private collection, USA) possesses this mechanism. A separate false keyboard that could be applied to any piano was invented in France by August Wolff in 1873. Although the radically reformed keyboard patented by Paul von Janko in 1882 does not shift, its keys are arranged so that the player's hands may shift over it and perform in any key without changing fingerings.

During the 20th century, several pianos with shifting keyboards (including one by Weser Bros., New York, 1940, now in the Smithsonian Institution, Washington, DC) were made for the American songwriter Irving Berlin, who could play only in the key of F. Many modern harpsichords are equipped with shifting keyboards allowing them to play both at ‘modern’ (a'=440) pitch and at ‘baroque pitch’ a semitone below. Contemporary electronic keyboard instruments and electronic play-back systems applied to pianos or other instruments are often provided with a switch or other mechanism to allow automatic transposition to any key.

Distinct from the foregoing instruments, which transpose by the intervals of conventional Western harmony, are certain Microtonal instruments, which may be considered to ‘transpose’ by increments smaller than a semitone. Among these was a ‘clavicymbalum universale’ with 19 keys in the octave, made in Vienna about 1590 and described by Michael Praetorius (Syntagma musicum, ii, 1618, 2/1619), which, presumably by means of a sliding keyboard, could be set to any of seven pitch levels within the interval of a major 3rd. In the late 19th and early 20th centuries some quarter-tone pianos and reed organs were made with two conventional keyboards tuned a 1/4-tone apart.

BIBLIOGRAPHY

BurneyFI

R.E.M. Harding: The Piano-Forte: its History Traced to the Great Exhibition of 1851 (Cambridge, 1933/R, 2/1978/R), 277–80

S. Marcuse: Musical Instruments: a Comprehensive Dictionary (New York, 1964/R), 529–30

G. O'Brien: Ruckers: a Harpsichord and Virginal Building Tradition (Cambridge, 1990)

J. Koster: ‘Pitch and Transposition Before the Ruckers’, Kielinstrumente aus der Werkstatt Ruckers: Halle 1996, 73–94

J.H. van der Meer: ‘Types of Transposing Harpsichords, Mainly Outside the Netherlands’, ibid., 95–103

N. Meeùs: ‘The Musical Purpose of Transposing Harpsichords’, Kielinstrumente aus der Werkstatt Ruckers: Halle 1996, 63–72

EDWIN M. RIPIN/JOHN KOSTER