It seems to be a law of nature that when we don’t quite understand the mechanics of something, we freak out about it. The first thing a little (and otherwise useless, as it happened) paring knife did upon being introduced into my kitchen was to cut me in my index finger. Why? Because I lost patience with its heavy-duty plastic wrapping which stubbornly resisted my opening attempts.
Do-I-Need-To-Fetch-A--Knife-To-Get-Out-This-One, I hissed, started to tear madly, the knife jumped out and got me. Very much like what happens in Planet Earth all the time.
When dealing with harpsichords, it is mostly the latter that gets damaged but otherwise the course of events is very much the same. The keyboard needs to be shifted a semitone up. We take out the little piece of wood at the right-hand side of the keyframe, we grab whatever knob or lever or side-of-the-frame is meant to be grabbed and we try to push the frame to the right. Something gets stuck. The sanest of us would perhaps shift the keyboard slightly back to the left and try again, slower – others don’t even go that far. Eventually everyone will end up anyway trying to force the keyboard through whatever obstruction there is, someplace inside the instrument, uttering a stream of oaths through clenched teeth.
Instruments with plastic jacks usually just jam in cases like that. Next time around, the harpsi-tech lifts off the jackrail and patiently extracts the (usually few) jacks that, by some quirk of construction or humidity induced key-warp have gotten jammed between the keys, and that’s it – no harm done. So here is already the description of how one solves a transposing jack-jam: hold everything, open the jackrail, see which of the jacks are stuck this time, carefully pull them up and proceed to shift the keyboard. It’s actually not that hard.
During my one-year interlude as harpsichord doctor at the conservatory in the Hague, the bass of the big 2-manual Flemish harpsichord in one of the studios once just didn’t play at all any more. I opened the jackrail and started extracting the jacks. But these were made of wood: twenty or thirty of the adjustment screws under the jacks had broken out because someone had forced the keyboard to the right without consideration. I don’t want to imagine how that sounded. Luckily the broken-out triangular chips of jack beside the screws were all still there. I lined everything up, took out all the adjustment screws, fetched some glue and glued back all these tiny chips. Then I did everything else to be done on that day, returning in the afternoon to re-assemble the action. Needless to say, the length of the jacks had to be individually re-determined and the staggering between the registers entirely re-established, a good hour’s work on top of everything else. Plus, the screw mountings in the jack ends were now much weaker than before, and every new attempt to bog up the action would be much more effective.
Change of scene. A very famous harpsichordist told his class that he actually didn’t really know why one can’t couple the manuals while playing on the lower keyboard — — In an otherwise very fine harpsichord, I found the coupler dogs (see Hubbard, Three Centuries of Harpsichord Making, plate XIII, fig 6) to be made of cross-grain wood. This would ensure their shrinking and expanding at similar rates as the keyframe does (a nifty idea), but let that harpsichord professor meet this instrument and the coupler dogs would break to bits like a bunch of fresh asparagus dropped on top of a flight of stairs. A horizontal grain direction makes these parts too weak to withstand attempts of coupling while playing.
In the first case, apart from the unlucky coincidence that made some of the adjustment screws catch the edges of the neighboring keys when transposing (an issue of giving the proper shape to the edges of the key ends and of proper regulation), there was surely nothing wrong with the design of the keyboard. Mounting screws under wooden jacks is – up to a certain level – a matter of taste, but no serious constructional blunder at all. In this example it was clearly the complete lack of concern and feeling of the person who caused the damage that caused the damage.
In the second case, the construction was simply too delicate for the conditions met out there. In fact, I ended up re-gluing coupler dogs in that particular instrument every month or so, and the harpsichordist I mentioned was not even teaching in the Hague. Using the coupler while playing seems just to be something some people seem to keep trying, and the mechanism can easily be made so it stays intact during these attempts.
What do I want to prove? Sturdiness of construction and mellow-, no, open-mindedness of the harpsichordists ought to meet each other someplace in between the extremes. And a little technical understanding, whether the maker’s or the harpsichordist’s (or both), helps a lot.