MIMF

Hello,

I'm a novice and am admittedly in over my head, but I've been researching building a bukkehorn.

http://en.wikipedia.org/wiki/Bukkehorn

I came to this forum because I was researching the cornetto family of instruments and came across references to your forum's spreadsheet tool:

http://www.mimf.com/old-lib/pub/cornetto.zip

which was mentioned in the MIMF Library here:

http://www.mimf.com/phpbb/viewtopic.php?f=32&t=921

Anyway, here is a video [15min, no narration] of a bukkehorn instrument being made:

http://www.youtube.com/watch?v=0Ft0i_2yfGM

Its rather boring, but 4:50 you can see him place the finger holes without any measurement, he seems to do it all bye eye. By 10:20 he works on the holes a bit more, apparently making adjustments.

So my basic questions are:

-will the cornetto spreadsheet tool be at all relevant to making a bukkehorn? If so, how do I begin to read it?
-what is the basic method for hole placement on a curved wind instrument? Measure along the inside curve, center, or outside curve?

Of course I've found some basic resources on tone hole spacing and design in other straight wind instruments, but i did not know if the cornetto spreadsheet was relevant, or if I'm missing other big concepts that are relevant.

Thanks for your patience and I understand if no one has the time to respond. Even if you just take the time to give me google search terms, book names, or articles to look up I would appreciate it.

After many attempts at PVC flutes and other instruments, I personally would not bother with the spreadsheet at all. They barely come close even for straight wind instruments with a consistent bore! The method used in the film will work just fine. There is always a tradeoff between hole diameter and position, and you can compensate for either by changing the other. A couple key points from the film:

1. After removing the inner part (whatever that is called) by boiling, he inserts a wire to find out where the natural plug starts, and then adds two fingers additional length to make sure he cut off the horn in the solid part of the plug to give sufficient space to make the embouchure hole. He seems to cut a 10-15 mm half-dome kind of embouchure into the end, not unlike where you blow a trumpet.

2. The finger holes were placed in positions that were comfortable to play, somewhere near the center of the arc. He went through a couple iterations until he found a set of positions that worked for him (at first I thought he was making two holes for each finger). If the holes are poorly placed, the instrument will be nearly impossible to play. Experiment and find what works for your hand in a relaxed grip.

3. The tuning was somewhat glossed over. The first thing to understand is that the primary pitch of any tube is determined by its length. The longer the tube, the lower the pitch. So the first step is to tune the main note by cutting the horn a little long, which means it will initially be flat, and then trimming to pitch. Every bit you cut off will raise the pitch of the instrument. There is no going back, so try not to take off too much at once! That builder probably knows from experience what the typical length of an F horn is (which is the pitch he made his to). You can also get that from the spreadsheet, and it the length would basically be a curved line along the center of the irregularly-shaped bore. Don't forget there is a solid plug on one end, maybe 20 mm thick, and the bore starts on the inside of that, so the bore length is not necessarily equal to the instrument length.

4. Next you can sand and shape the flat areas around the holes, to make it more comfortable to play, and also to give the fingers better seating to seal the holes than the normal ribbed antler surface. Do this before tuning, because it will affect tuning to a small degree.

5. Drill a small diameter hole (~2 mm) at each finger position, and at the thumb position on the back. Cover all holes except for the bottom one, and slowly enlarge that hole until the instrument comes to the right pitch for its second note. In the video, the builder sometimes used a special knife to ream the holes, and sometimes he just reached for a larger drill. You might also use a small round file. Go slowly until you get the hang of it. Once the two bottom notes (all holes closed, and all but the bottom hole closed) have the right relative pitch, start increasing the diameter of the second hole until the first three notes are correct. Repeat until all holes have been tuned. The enlargement of holes will affect the pitches a little, so you generally have to go through the process a second time, although the adjustments on the second go-round are much finer.

If you can afford the time, I would strongly suggest making a few PVC flutes first to get the tuning procedure down. You can make one in an hour or so, and a $2 tube of PVC will give you many days of tuning pleasure. Making one out of a horn won't seem as complicated after you have done it a couple times.

Good luck, and, of course, please post the results here! Also check the library. I think someone may have once made a shofar (another horn made out of a horn) a while back and posted it.

Thanks Jim, I'll be applying all your advice. I also picked up a length of pvc pipe yesterday so I can practice the tuning procedure over the weekend. I'll post the results with the actual horn here, in time.