[Harp-L] Re: tunable harp - thumb piano

["jross38@xxxxxxxxxxx" <jross38@xxxxxxxxxxx>]

Phill writes:
"The thumb piano or kalimba uses a series of tine that are plucked to create the sound. The small hand-held device (often played by thumbs) is tuned by adjusting the length of individual tines. <snip>But the significance is that the Kalimba is tunable. "
Yes, but the tuning range depends on several factors.  With kalimba/Sansa style instruments have straight tines which are of uniform thickness for all keys.  With these the pitch is determined solely by length--longer lower, shorter higher.  But, this doesn't entirely translate to how most harmonicas are built.  Reeds are scaled differently from bass to treble in width, thickness and so forth--with weights added to the lower reeds.  In that way, the harmonica resembles more the forms of mbira typical in Zimbabwe and a few other places, where the tines are of differing thicknesses depending on pitch, with flattened and forged ends to emphasize certain harmonics.  On these, fine tuning is adjustable by altering the length, but the range is significantly less than with the simpler model (having no desire to radically retune my mbiras, I am not interested in exploring those limits comparatively--but one is a matter of fine tuning and the other of gross tuning). 
Now, there is no reason why you couldn't have the harmonica reed's pitch determined solely by length, with no weights or the like, but how this might effect reed response is a question.  Also, you could accept a more limited retuning range via the mechanism in turn for better scaling.  Indeed, tuning free-reeds by altering the length is not a new idea at all--it dates back to the early 19th century.  But, there are very good reasons, IMO, as to why all current free-reed instruments used fixed-pitch instruments.  One is the complexity and space needed to create an adjustable system.  The other, and probably most likely reason, is the instability of pitch with free-reeds tuned by a device which limits the length of the reed.  

"the same thing might be feasible for a tunable harmonica. "
As both Winslow and I pointed out, these sort of systems have existed for nearly two hundred years.  This discussion has been about the problems one would encounter in creating such a system for a harmonica--where space is a major issue.

"If someone were to suggest that someone invent a wrist watch today from scratch, the immediate response would be that it would be impossible to make something with such small parts ever work."
No one has suggested that making a harmonica which tunes in this manner is impossible.  Just very difficult.  Clockwork style mechanisms are the best way to do this, IME, but they are far from perfect.  One factor to consider, is that if you are only clamping one side of the reed (which is possible), you will need very tight tolerances for a mouth blown instrument, because air will be lost behind the clamp.  If you are clamping both sides of the reed, it might be more stable, but also significantly more complex--and probably the same air-loss issues.
"And while we sit around arguing about how impossible a tunable harmonica is, somebody will come up with one. "
So done already did, in a sense.  The technology is ancient and tried.  What I and others have been discussing is the feasibility and practicality of adapting such to the harmonica--as the possibility of tuning free-reeds via a length fixing device is settled.  I am probably the only person on this list (or likely any other harmonica list) with significant experience in tuning free-reeds in this manner, and I have certainly considered making a harmonica tuned this way over the years.  But in the end, I don't think it adds that much--easier to just carry more harps.  If someone wants to be inventive, I'd encourage them to focus their efforts in other ways.  And again, this is not speculation for me--I have real world experience with tunable length free-reeds and don't consider them worth it.  Indeed, if you really want a tunable mouth blown free-reed instrument, the Claviola would be the first place I'd look.  And then see if that style of free-reed could be converted into a more harmonica-like instrument.


JR Ross