fortepiano stability

[Stephen Birkett]

Talked to Paul Poletti recently on the subject of fortepiano
stability. I've appended his comments in our discussion
below...sorry if it's a bit long, but it seems to give a good
perspective on the recent discussion and offers some practical hints
that could be useful.

Comments from Paul Poletti:
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My two cents on tuning is that it is not all that mysterious. I
reckoned the other day that I have tuned for close to 1000 concerts,
many different pianos both copies and originals, and almost every
player in the scene, both European and American. I've tuned for solo
concerts, chamber with strings and winds, and concerti. I agree with
you that any piano which is abused will not stay in tune. Why should
it?

Basically, aside from abusive playing, two things will make a piano
go out of tune: moving and changes in environment. Temperature and
humidity will affect all pianos, even modern pianos, some more than
others of course depending on the way the cases and boards respond. I
don't think stability is necessarily desirable, at least not against
weather, because stability usually means massiveness. The early
builders were still working with the idea of making a structure only
as strong as it needs to be, or as weak as possible is another way of
looking at it. Perhaps Graf, Streicher, and Bleyer were the first to
depart from this concept with the stacked frames. Graf seems to have
gone to far, since his early instruments are all oak and later he
goes back to oak-spruce-oak-spruce. I'm not surprised that some
"Steins" you know are very stable. I know of no real Stein copy in
America, and all the Zucky Stein-like things are quite over-built.

I've moved instruments from LA to San Francisco and from Amsterdam
to Paris and had them be perfectly in tune when they come out of the
van, but miserable after sitting a few hours and adapting to the
local environment. I recently shipped a piano from Amsterdam to
Belfast by airfreight. It was in good tune when it went into the
crate. One week later when it came out of the crate in Belfast, it
was ice cold and miserably out of tune. After sitting for several
hours and coming back to a temperature and humidity that was quite
similar to Amsterdam, it went by itself back into perfect tune. I've
had instruments that have sat in a hall for days perfectly stable go
berserk when thunder storms moved in in the middle of the concert.
The things are great hygrometers.

Generally the pattern is that the extremes of the instruments go in
opposite directions: if the weather gets dry, the board flattens,
lowering the tension on the whole instrument, but since the tension
in the bass and tenor is so much higher than in the treble, the
structure relaxes, the frame expands, pulling the treble sharp. The
reverse happens when the weather gets wet.

Moving pianos can also cause problems if you don't do it right. The
trick is you have to keep the same three legs on the ground. If the
piano has 4 or 5 legs, you have to choose three (the tail and bass
keyboard will of course always be two of these) and make sure it
stays the same where ever the thing is moved to, whether it be 500
miles or one foot (no floor is flat). This is why you see the
historical shift to three legs around 1820. I think the two front
legs are the best, but some people like to take the cheek/bentside
leg. Makes no diff, really. You can easily prove the importance of
this by lifting the right front corner of a well-tuned five-octave
piano with your knee whilst playing it. You can hear the treble go as
you lift, and return to good tuning as you lower it.

Stage light also can ruin a tuning. Hundreds of people breathing can
ruin a tuning. In general, the modern concert life places such
ridiculous demands on instruments that it is a wonder it works at
all. Any time you hear a well-tuned fortepiano in concert you should
count your lucky stars. They were never made to withstand that sort
of jet-set concert life. They were made to sit in music rooms and
salons of stone and brick buildings which stayed pretty much the
same humidity and temperature year round. Our workshop has stone
walls and brick floors on sand, both of which act as a tremendous
moisture sink. The humidity never goes above 75% and never below 60%,
regardless of outside conditions or winter heating. I would imagine
that most of northern Europe had similar conditions two hundred years
ago. It is the modern centrally heated and cooled environment that is
death to instruments, since humidity is almost never monitored or
controlled.

On the topic of hard playing, when you read Streicher and von
Schonfeld, you realize that they are talking about subtleties of
touch which are never approached in modern times. The halls are too
big and many fortepianists still play too much modern piano. The best
players (not only in terms of tuning but also in terms of control and
color) are those who also play clavichord. Clavichord will simply not
take abuse. Either you adapt to its terms or you get no sound.

Paul Poletti