Instruments of Roman Sukac & Michael Scheer
CLAVICHORDS
The fretted South German hexagonal, anonymous, about 1600
Clavichords are subdivided into fretted and unfretted instruments. Fretted clavichords are instruments which were built from renaissance until baroque period - there is one string or string choir 2 or 3 keys. The key levers were arranged in the way that the distance between the tangents corresponds to the proportions of a semitone. That's why the keys of these instruments are not parallel but appropriated croped. This limits the compass to four octaves usually. Clavichords and other keyboard instruments (e.g. organs) were built with up to 6 octaves during the Spanish high baroque and classical period.
The South German hexagonal (the case is an irregular hexagonal) is a table instrument without stand which is tripple fretted, e.g. the tones bb - b - c are on one string and cannot be touched at the same time as a small or a big second. The fretting of strings has different benefits: because you need less strings for a certain quantity of keys, the soundboard is less strained and can swing easier. Also a meantone temperament is easier to tune because if c is tuned the notes b and bb are also already tuned. If the third c - e is correct, f and #f are also correct. Then the pure third according to d - #f is easy to find with the neighbours #c and #d and so on. In contrast to fretted clavichords the unfretted ones from the high baroque have one string or string choir for each tone and a larger compass.
The rebuilding of this hexagonal has small modifications: the compass has been extendes from C/E - c''' to full four octaves, the tone fretting has been reduced from tripple to double (bass octave is unfretted) and the temperament has been adapted from a South German meantone temperament ("Esterreicher von Anieres"). The case is made in maple and waxed, the keyboard is covered with plum / ebony and the rose which is missing on the original instrument is an Italian cut from parchement.
The unfretted clavichord according to Johann Heinrich Silbermann, Strassburg 1775
The carpenter Michael Silbermann (*1650) from Strassburg had 3 sons from those one (Abraham) died early, the both others were the famous organ, harpsichord, clavichord and fortepiano builders Gottfried Silbermann (1683-1753 and friend of J. S. Bach) in Freiberg and Andreas Silbermann (1687-1734) in Strassburg. The fourth and youngest son of Andreas was Johann Heinrich (1727-1799) who learned the instrument building from his father Andreas and with his uncle Gottfried. He was a famous componist and organist. He especially has been praised as a master of instrument building, e.g. by Forkel in the "Musikalischen Almanach" 1782: "... all over the musical world his instruments are that famous and praised that you can say nothing more about their praise. Both, as well as harpsichords also pianofortes and clavichords ... are especially sweet in sound and the fantastic craftsmanship."
The sample for the rebuilding has been a clavichord with two choirs from 1765 in the "Germanisches Nationalmuseum" in Nuremberg.
The instrument and the stand are from walnut and waxed, the keyboard is covered with ebony and bones. Its compass from FF-f''' and the pitch 406 Hz (392 Hz) with brass strings or 430 Hz (415 Hz) with iron strings.
The fretted Spanish clavichord with six octaves according to JosŽ Grabalos, Tarazona about 1790
In the MUSEO DE LA MUSICA in the Catalan capital Barcelone an external inconspicuous clavichord from pine is placed with naturals from box and sharps from palisander. It surprises with its unusual big compass from six octaves (FF-f'''') and a strong tone which is clear up to the discant. A slip of paper is glued on the soundboard which identifies the builder as JosŽ Grabalos / Contralto en Tarazona. It's obvious that it is about Taranzona near Zaragossa as there was an instrument building centre where also e.g. organs with unusual compasses and sound colours were built. Until now there is almost nothing known about this instrument and its builder - probably because of the unatractiv plain surface and the feeling that the early classic period belongs to the pianoforte. The strings of the 1st bass are single and wound, from F the choirs are double with brass unfretted, and the upper four octaves are fretted with iron. The scaling of the strings points at a pitch of 415 Hz. The original temperament is a Spanish meantone with thight big thirds (2/7 syn. comma). The rebuilding also can be tuned with a 1/6 pyt. comma modified Valotti temperament by bending the tangents.
The two manual fretted clavichord based on the Silbermann instrument, Jestetten 2005
From the intense collaboration with the clavichordists Johann Sonnleitner and Stefan MŸüller the wish for a two manual clavichord came through. Also literature like the Goldberg Variations or organ pieces should be plaid with this instrument - pieces which pretends two manuals. To redevelop the "old practice instrument" of the organists, two Silbermann clavichords with five octaves have been built on top of each other. So that the keyboards are not too far away from each other, the keyboard of the upper clavichord has been put 7 cm lower - so the keyboards almost have the normal distance from two manual instruments. Both instruments can be plaid also single.
The two manual pedal clavichord based on the Silbermann instrument, Jestetten 2005 (photo see above)
Heinrich Nicolaus Gerber, *1702, was organ and harpsichord pupil of J. S. Bach. In 1728 he became organist in Heringen and 3 years later in Sonderhausen. Apart from his church works and his teaching, he even found time to build - with help of a carpenter - a 12-registered organ with pedal. In 1742 he built a two manual pedal clavichord in the shape of a pyramid with 10 possibilities to change the sound.
In 1760 a two manual pedal clavichord with compass C-e3 (8’ double choir) for the manuals and CC-c (16’/8’ double choir) for the pedal was built in the workshop of Johann David Gerstenberg, organ builder in Geringswalda. This instrument is now at the university of Leipzig.
These instruments were the stimulation to continue the tradition of the pedal clavichord. The rebuilding is made according to Joh. H. Silbermann, Strassburg 1775, to redevelop the "old practice instrument" of the organists. So two 5 oct. clavichords with compass FF-f3 (8’ double choir, unfretted) made from walnut have been built on top of each other. For that the distance of the both keyboards is not too, the keyboard of the upper clavichord has been put 7 cm lower - so the keyboards, covered with ebony and bone, almost have the normal distance of two manual instruments. Both instruments can be plaid single or coupled. The pedal clavichord - also from walnut - with compass CC-d (16’/8’ double choir, unfretted), can be registered single or coupled. The stringing is based according to the Silbermann scaling in brass and the pitch 392 Hz.