Re: Reed Tuning/wondering pitch

[Pat Missin <pat@xxxxxxxxxxxxx>]

Jimbeau wrote:

>So Pat, what method(s) do you use to warm up the reeds, both in the repair 
>shop and on location at a performance?

In the workshop I usually use a microwaveable gel pack, as used for
sporting injuries and the like. If I just need to touch up the tuning
on a couple of reeds of one of my own harps, I may simply stick it
under my arm for a while - I don't do that with my customers' harps,
of course!

For performance, I'm not all that fussy most of the time, just
providing the harps are not below room temperature  - assuming the
room isn't an igloo. I do prefer to have any valved chromatics warmed
slightly to reduce the likelihood of valve problems. Also, if I am to
be playing a piece which really demands very pure blow chords, I will
carry the appropriate harps for a while in my pockets, or again, under
my arm.

However, keeping the harps warm for tuning is generally much more
critical than warming them for performance. It's not all that common
that you will spend several minutes onstage blowing the same reed
without drawing now and again. Usually a quick draw in the same
chamber will reduce any minor condensation build up on the draw reed.
Tuning can be a whole different ball game, as you can often spend
quite a while blowing a reed, tweaking it a little, blowing it a bit
more, etc. Keeping the reeds warm whilst tuning is essential, IMO.

As I'm on a roll, here are a few more tips you don't find in the usual
"how to" guides.

Some degree of pitch with playing pressure is normal. Usually, the
lower the reed, the more it will tend to drop in pitch as you increase
the pressure. This can actually be very helpful when tuning. If you
play an octave and it beats a little, you can tell what needs to be
tweaked by varying the playing pressure. If the beating increases when
you blow harder and decreases when you blow more softly, then the
octave is probably slightly wide - you need to sharpen the lower note
or flatten the upper note. If the beating decreases with higher
pressure and increases with lower pressure, then the octave is
probably slightly narrow - you need to flatten the lower note or
sharpen the upper note.

The same thing can be used to obtain precise tuning of other just
intervals, or indeed a tempered interval if you know how much you want
it to beat.

Although most reeds flatten a little with increased pressure, if the
pitch changes a lot when you blow or draw, that is usually a sign of a
problem with the reed. What constitutes "a lot" of pitch change is
something that is hard to define precisely in an email, but experience
will teach what is normal and what is not. If you have your doubts
about a reed, try playing it normally, then dropping your playing
pressure all the way down to the softest you can manage. If the reed
suddenly starts to play very sharp when you are at a whispering level
of breath, then it mostly likely has a stress fracture towards the
root. Often you can diagnose a fracture this way long before the reed
actually dies. Sometimes you can visually confirm the problem by
gently lifting the tip of the suspect reed - a healthy reed should
have a nice curvature to it, but a reed with a stress fracture will
often have a slight "fold" across the reed at some point. Don't even
waste your time trying to retune one of these.

Just to make matters worse, some reeds, particularly the higher
pitched ones, will actually rise in pitch with increased playing
pressure. I have no idea why this is, but the same phenomenon has been
confirmed in studies of free reeds used in organs. This is most
notable on the upper blow reeds of the highest keyed harps. No easy
way around it, just try to tune them so they sound as good as
possible. 

However once again, if they vary by than a few cents when you play
them harder, this is often a sign of defective reeds - most often they
have been thinned too much towards the tip.

I also find that lowering the pitch of a reed by adding solder to the
tip, or raising its pitch by <cringe> adding solder to the root can 
also affect how the pitch varies with changing pressure.

 -- Pat.