Re: [Harp-L] tuning limits

[G <gigs@xxxxxxxxxxxxxxx>]

Date: Thu, 14 Apr 2005 18:13:19 -0700 (PDT)
From: Paul Bowering <paul_bowering@xxxxxxxxx>
Subject: [Harp-L] tuning limits
To: harp-l@xxxxxxxxxx

>I'm experimenting with some altered tunings and I'm
>wondering how many semi-tones a reed can reasonably be
>retuned before you risk failure? Can lower picthed
>reeds withstand greater deviations from its original
>pitch than higher reeds? Does it matter if tuning up
>or down, etc.
>
>Paul 

Hi Paul,
  The answer is complex.  
  When removing material I find that I can lower the pitch of reeds a great
deal more than I can raise them before their performance suffers.   
  With the highest reeds, say the top reeds of a key of C 270, it takes
care to raise them even a semitone, if you remove too much brass in the
process the pitch starts to go ~down~, except when you play it very very
gently and it'll play very high - the problem is the end of the reed can no
longer handle the force flops around.
  At the other end of the spectrum I've found I can lower the lowest reeds
by 4 or even 5 semitones, by removing material at the root of the reed.
Eg. Tenor C 270, or Super 64X bottom octave.

As for an average reed, depending on their pitch relative to their
dimensions, they can generally (with care) be raised up by a minor third -
I know some people have successfully raised them by more, but I've found
its more efficient to simply replace reeds that need to by raised by a
major third or more.

  I've found that lowering the pitch of reeds is easier: you don't need to
worry about catching the tip of the reed which can lead to ruining the reed
in the blink of an eye; I can lower the pitch of the reed further than you
can raise it before the reed's performance suffers; and theres the happy
side effect that any tuning gashes can be polished out while you're tuning
the reed down.  

I've had people approach me privately saying they don't know what I'm
talking about when I mention "tuning gashes" ... in not so many words. So
I've put up a very clear image and an explanation here
http://www.angelfire.com/music/harmonica/tuninggashes.html

To summise, in general when retuning a harmonica, the more extreme the
change, the more I prefer to start with reeds that are higher in pitch than
what I need, rather than something lower.  There are exceptions, and there
are aspects to take into account when working out the most efficient
approach. Barely a hard and fast rule.

More related information here
http://www.angelfire.com/music/harmonica/harptechtips.html

Cheers,
-- G.