pitch in 1860

[Stéphane Collin]

Hi Calin.

In many original Pleyel pianos in the 1840-1860 range, I noticed that, when 
tuned at 440 Hz, in the 5th or 6th octave, some notes have a funny, tubby 
sound, just like if the strings were not tensionned enough.  On the one I 
have, when tuned higher, this disappears, and the sound comes back to 
something more normal.  Unfortunately, on a piano with original (or very 
old) strings, I hesitate much to do breaking tests, unless I have to 
restring anyway.
For Bechstein, I am quite sure that from the beginning they used Krupp steel 
similar to modern steel, and kind of low tensionned : on a 1871 Bechstein 
with most probably original strings, the strings average broke at a minor 
sixth above the note's right pitch referred to A4 = 440 Hz, which the new 
Röslau strings did too.  That was the motivation of Carl Bechstein : build a 
piano that could hold up under the agressive powerful playing of Franz 
Liszt, who liked breaking strings in front of young ladies.  On the Pleyel 
1864 I'm restoring now, I'm not sure that the strings are original.  But 
they broke average an augmented fourth above the 440 pitch, while Röslau for 
the same note, same diameter, broke a perfect fifth above, and the Pure 
Sound broke as soon as somewhere between a major third and a perfect fourth 
above.  Maybe these strings were end 19th Firminy wire, as I know the piano 
has been upgraded at the Pleyel factory about that time.
Anyway, in your situation like in others, I would trust my ears, and try to 
reach the best sound, which I'm sure they did too at the factory.  Not 
enough tension = funny sound, more tension = cleaner sound (less 
inharmonicity due to increased elasticity of wire), too much tension = much 
less sustain, sound getting thinner (less personality) and strings breaking 
on heavy playing.  (Ah, and also structural integrity of the wooden parts 
sooner prone to failure.)

Best regards.

Stéphane Collin.