Monday, January 27, 2014

The Key Box

A year later, I'm picking up where I left off in my blog posts.  The nyckelharpa is finished and I'm thoroughly enjoying playing it!



When I left off, I was beginning the keybox.  A nyckelharpa is bowed like a violin.  However, to get the variety of notes needed for a melody, it is fretted, but not in the usual way . . . You need a keybox!

A keybox holds --ready?--  the keys!  The keys hang downward away from the strings and hold the tangents--pieces of wood sticking up at right angles to the keys (some of them passing through one or two layers of keys)--which, when a key is pushed "upward" or "in" (NOT like a piano!  Think of a sliding motion rather than a pressing down motion), moves the tangent against the string and gives your variety of notes.  (This is where I could start going into details about string length and diameter, and how these variables apply in a harmonic curve.  If you're curious, that will be at the bottom).



The keybox is like a layer cake.  I began with the bottom and worked to the top, because each layer must fit and work with the layer below.  It was tedious.  This is the bottom, which is screwed to the neck of the instrument.  I used a small saw where I could, but mostly used a chisel to shape the odd angles.








My fingers are gripping the part which attaches to the neck, and the slight "rise" is where it begins to hover over the soundboard.












Simultaniously, I began ripping blanks for carving keys.  Whew!  I learned from the PBS long-running show, "The Woodwright's Shop", hosted by Roy Underhill, to cut around the corners in order to end up with an even thickness.









Hours, days, weeks later . . . I have some nice blank sheets to cut smaller pieces from.  Then I switched to my pocket knife to "whittle" the keys to fit, each one individually.  (the ultimate "custom job").







The keys need to rest in slots.  Think of a turret on a castle.  After carving the bottom "layer", I began on the next layer and discovered I could use my saw to cut the depth, and then use the point of my knife to score stopping point.  I could then pop the waste out.  Occasionally, I would also pop out the "tooth" which was meant to stay, but wasn't an issue and was easily glued back into place.






Lots of intricate cutting ahead.  You can see the bottom pieces are just right!  On to the next layer!











Harmonic Curve & etc:
Imagine a grand piano (or a harp).  When you sit at the piano, the bass (low notes) side extends further away from you and the treble (high notes) side is pretty short.  That's a harmonic curve.  You can get fancy and scientific with the diameter (thickness) of the strings vs. the length of the string, but BASICALLY a long string will have a lower sound and a short string will have a higher sound.

A string has a "vibrating length"--the string starts at one point and stops at another point and what is in between those points can vibrate freely.  When you fret the string (press it against a different point along that vibrating length) you essentially make it shorter, which makes the note sound higher.

In the case of my nyckelharpa, all the strings have the same vibrating length, so how do I get so much variety from very high and squeaky to low and rich?  You change how thick the strings are!  The lower notes come from thicker strings.  Like a wind chime with pieces of metal rods:  the really high tinkly sounds come from thin and short rods--the lower gong-like sounds come from longer thicker rods.  If the rods weren't made thicker, they would have to be much longer to get the same low note (and you'd have to find yourself one heck of a tree to hang it on!).

That's my short and condensed version.

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