[CAUT] harpsichord (was Re: temperature and pitch)

[Paul T Williams]

Great advise, Fred!

Yes we have several recitals through the year requiring a harpsichord. 
I'll tuck this nugget of info into my nearly full brain for the next one!

Paul



From:
Fred Sturm <fssturm at unm.edu>
To:
caut at ptg.org
Date:
12/18/2009 06:48 PM
Subject:
Re: [CAUT] harpsichord (was Re:  temperature and pitch)



On Dec 16, 2009, at 6:33 PM, Fred Sturm wrote:

> Some of this is temperature, some is RH.


                 I thought I'd give an update on the last two days with 
the 
harpsichord, as there were a couple interesting features. Wed at 5, as 
stated earlier, I tuned when the hall was 76F/10%. 24 hours later, I 
arrived to find the hall at 70F/9%. The hall manager told me she had 
kept the hall dark all day to get the temp down, as it had got above 
80F during rehearsal and there were complaints. (And keeping the 
lights off is really the only direct temp control she has, as 
otherwise it is just dependent on what the HVAC system does, and it 
doesn't keep up with the heat the lights put out - without lights, it 
will hold the 70-71 target quite well). So it was cooler (meaning 
sharp), but also the instrument had baked at high temp and dry 
conditions the night before, so the board and bridges would have 
shrunk a good bit.
                 I checked tuning and found the bass (brass) strings sharp 
by about 
4-8 cents. So the cooling had more of an effect on them than the 
drying. The steel strings, though, were 6-12 cents flat. I figured at 
this point the instrument was approaching coming into stability with 
the dry environment. This being dress rehearsal, I took a little more 
thought and care. I tuned to 441, and tuned the bass strings up 1-2 
cents above that, as a way of hitting an average mid way through the 
rehearsal that would be reasonably close. The bass octaves can't be 
much narrower, or they will sound too bad as a first impression, and 
the conductor will freak (he conducts from the harpsichord).
                 24 hours later, tonight, first performance. 70F/11%. Bass 
is where I 
left it (though I am sure they went flat during rehearsal last night). 
Steel strings are 2-6 cents flat. I tuned as I did last night. Things 
will be fine (they'd be better if I came at intermission and pulled up 
the bass, but money is tight).
                 Anyhow, I hope this description is helpful to some of you 
who fool 
with a harpsichord once in a while. The real lesson is what happens to 
the brass strings. Temperature rules with them, and it takes very 
little change to produce a big result. Mostly you have to grin and 
bear it. The other thing is that the soundboard and other wooden parts 
adapt a lot faster than on a piano. A lot thinner and less bulky.
Regards,
Fred Sturm
University of New Mexico
fssturm at unm.edu







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