Restoration Report

on the
Michael Thomas French Double Harpsichord in an antique case
privately owned in Singapore

NASA VISIBLE EARTH

Condition at first examination
The harpsichord was first seen in Singapore in August 1993. At this time it was quite unplayable, showing signs of humidity exposure with mould and insect attack, and tension damage with past attempts at repair and modification. The instrument was strung a little on the heavy side. The bentside hitchpin rail had come unstuck. The registers had frozen, the wooden jacks had individually seized in the registers as well as their axle pins corroding, and there was insufficient clearance for the transposer to work. The soundboard had cracked in many places as well as being warped. Repairs made over the past decade during two visits to a famous European workshop to correct the loss of soundboard crown resulted in a complete lack of resonance.

Arrival at the workshop
The instrument was crated and airfreighted to Sydney in September 1993. Prior to dismantling, the existing strings were measured, and a rubbing made of the layout of the instrument. The Michael Thomas English soundboard dating from 1979 was removed in one piece, and the extreme rigidity found to be caused by recently fitted heavy ribs attached directly to the upper braces, effectively preventing any soundboard drop but also completely deadening the tone.

It was considered necessary to replace the Michael Thomas soundboard and a decision was made not to sacrifice the end quality by attempting to reuse the old bridges, nuts and rails. A new board with matching wrestplank veneer was prepared using the highest quality twenty-year old Swiss pine, with new bridges, 4⁠´ hitchpin rail, and a more traditional barring arrangement with traverse ribs in the soundboard rose area. A Ruckers-style rose was fitted to allow internal case ventilation because of the solid bellyrail dating from Dolmetsch.

No Dolmetsch internal bracing remained. The recessed bottom was reglued so thoroughly during previous repair that it was judged impossible to remove without destroying it, so all the soundboard and case work was completed from the top. The soundboard support blocks added to the upper braces during a previous repair were removed. The upper bracing was found to be sufficient after the addition of two upper brace glue wedges against the bentside liner of the two treble-most braces. Because of the complete absence of lower bracing, two lower frames were added. The existing gap spacers were retained. The bentside and its liner were reglued in the treble where they showed signs of delamination. The bellyrail capping which had come almost completely unstuck and swung forward, was removed, the red paint cleaned from the gluing surfaces, and strongly reglued to the bellyrail. The new 4⁠´ hitchpin rail was firmly wedged in place at the treble end.

Internal bracing 24K jpeg The wrestplank veneer was removed and the wrestplank found to have been resurfaced in the 1979 English rebuilding with a 12mm plywood facing. It was decided to use the existing tuning pin holes after the new veneer to match the new soundboard was fitted. New nuts were fitted, but the existing buff batten and carved beech stop levers were reused. Work on the new soundboard was carried out at very high humidity, and installation took place at 80%, slightly drier than its expected surroundings in Singapore. A deliberate crown was built into the soundboard by screw support of the 4⁠´ hitchpin rail and at several points under the 8⁠´ bridge during the soundboard installation.

A single piece bentside hitchpin rail was used with new mouldings around the soundboard perimeter. These parts, often prone to tension failure when poorly glued, and two wrestplank side cleats which were previously just screwed, were glued using the strongest water resistant aliphatic resin glue.

Soundboard decoration
The 1979 soundboard—but not the wrestplank, for some reason—had a soundboard painting. Although the soundboard area is somewhat shorter than French five-octave instruments from the mid-1700s, by judicious reduction in size and spread of various elements, the replacement soundboard was decorated in French style by Diana Ford using motifs and a modified layout with reference to the Goermans/Taskin in the Russell Collection in Edinburgh without blue borders—the state that particular instrument has been in since 1784.

Stringing
The tuning pins were cleaned of their worst corrosion, and each one reused in their respective hole. The new iron hitchpins were cadmium plated to delay rusting. It was found that accumulated errors from the various alterations the instrument had seen over the years resulted in poor string spacing in several localities, especially in the treble position of the 8⁠´ hitchpins. These were subsequently remarked, and other gross errors corrected for consistency. Computer modeling was used to examine the strings from the European alterations, and determine the best schedule for restringing with historic-type wire. The original total tension of 1048kg was reduced to 808kg. The iron wire, already tinned, was rubbed during the stringing process with a light residual anti-corrosion solution to help further delay corrosion under the extreme humidity conditions found year-round in Singapore.

String tension chart 28K jpeg

Keyboards
The keyboards dating from 1979 with their various later amendments were reused after cleaning, polishing, leveling and correcting gross spacing errors. The original balance punchings showed signs of severe insect attack, so the best were used for one keyboard and new ones fitted for the other. Modification was also made to the coupler tracks to help prevent askew movement, but both left and right coupler tracks are very small and the arrangement still remained somewhat flimsy. The transposing piece was reduced in thickness to allow sufficient clearance for correct operation of the transposing mechanism. Two keyboard height adjustment screws were fitted through the bottom.

Action
New beech registers for the new plastic jacks were made using the existing registers as models to preserve the non-standard key spacing. Small capstans were used to assist in ease of adjustment after acclimatization because lack of either a spine or cheek window would make it impossible to remove the registers in this instrument when the strings are in place. The original lower guide was split with the lower keyboard choirs supported from a thick batten screwed to the bottom. This batten was removed, and the scheme changed to allow a single lower guide, with all three choirs suspended just below wrestplank level. A new dampchaser was fitted with its power cord penetrating the front bottom, to replace the previous dampchaser whose cord was obtrusively routed through the keywell.

The heavy wooden jacks from 1979 were not reused. The instrument was jacked using modern Zuckermann lightweight brown plastic jacks with celcon plectra for the 8⁠´ choirs and thin delrin for the 4⁠´. (Thin celcon was not yet available.) Final voicing and regulation were carried out at A415. The modern red thick jackrail felt was replaced with nailed layers of loose woven hopsacking, and the critical height adjustment made to all three choirs in the jackrail with tapered wooden shims or additional hopsacking strips where necessary. A strip of tapered deer skin was guillotined for the buff stop pads.

Case completion
The case was washed down with antiseptic solution to destroy mould spores. The areas of the decorative paper damage around the soundboard rim were carefully painted black to improve appearance, and minor case scrapes were touched green. A new lid stick, music desk and traveling trestle stand were made, and a custom made padded cover supplied for the future protection of the harpsichord.

Conclusion
While much of the instrument was not new, there was no evidence found during the work of either material, design or construction technique to suggest any part of the harpsichord itself once dated from earlier than Dolmetsch’s time. Several features of the instrument’s construction point to this conclusion, including the corner joints, recessed bottom, laminated bentside, heavy internal liners, single piece bellyrail, signs of the Dolmetsch internal bracing (removed in past work) and the red painted interior.

Perhaps close examination of the Louis-XVI style stand might reveal that it had indeed survived from the eighteenth-century and Dolmetsch made this instrument to suit. The old 8⁠´ bridge reused by Michael Thomas on his 1979 soundboard was originally single pinned and the second choir subsequently added with a different pin type. This was most likely Dolmetsch’s bridge, but perhaps closer analysis of the bridge pins will reveal more of its history.

All displaced parts were packed for return of the instrument by airfreight to Singapore in early September 1994.

Since then, due to the generosity of the private owner, the instrument has added much to the musical life of Singapore. It has been used by visiting artists including Trevor Pinnock and The English Concert, I Fagiolini and The American Bach Soloists. The harpsichord made a subsequent visit to the workshop in 2002 to correct serious termite damage and continues to sound and play exceptionally well in the adverse tropical climate.

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