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Strappadolin

A type of musical insturment.
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Strappado refers to the torture scheme whereby an unlucky individual is hung by their arms and weights are attached to their feet and the whole thing feels horrible for the person.

The stappaodlin relies on a similar arrangement, but nobody is tortured. Finely wound steel strings are hung by their "arms" from a rafter mounted 15 feet high, and different weights are attached to the different strings "feet", providing ample tension. Now, when the strings are stroked they make their ever soothing sounds. It is expected that this would not sound anything like a harp, or a guitar, piano, or anything of the sort.

daseva, Apr 18 2008

Weighted Strings. A pendulum passes a magnet, with mechanical vibrations. http://www.neilfeat...eighted_strings.htm
With sound clip. Wow! I'm in Ambient heaven! [Amos Kito, Apr 18 2008]

Vincenzo Galilei http://galileo.rice.edu/fam/vincenzo.html
Performed experiments on lengths and tension of strings on weights. He's said to have had a "room full" of such strings. [Amos Kito, Apr 19 2008]

Strike a Chord: Pizzicato Piano http://www.questaco...pizzicato_piano.rtf
with equations! [Amos Kito, Apr 20 2008]

The Earth Harp: World's Largest Stringed Instrument http://youtube.com/watch?v=lv26V1orb0Q
Not plucked. The strings are rosin rubbed. [Amos Kito, Apr 20 2008]

[link]






       Ah. I was thinking this involved tuned prisoners.
DrCurry, Apr 18 2008
  

       how is this pronounced? I read it as "strap it all in"
jaksplat, Apr 18 2008
  

       Stress the second and fourth syllables, and you should be fine.
daseva, Apr 18 2008
  

       Envision each weight being shared by two wires. The wires are attached at opposite ends of the ceiling so the affair forms a letter V. Several are arranged in parallel. The weights are round steel balls. This is now like the executive toy where one ball swings to hit the next, and the wave goes back and forth. By using wires instead of string and affixing the wire in a way to minimize dampening, the wires should vibrate on each strike, and the apparatus play a series of notes forwards and backwards,
bungston, Apr 18 2008
  

       Admittedly, you can really just about envision anything with simply weights and wires. I would also like to see smaller wires and smaller weights attached to the ends of the larger original weights, which may account for octaves and tonal variety. You are on the hoped for track, bungston. There's no reason we can't stack these arrangements all the way up.
daseva, Apr 18 2008
  

       This would be a swell museum exhibit. One could play these wires by whacking the weights with a big gnarly mallet.
bungston, Apr 18 2008
  

       Erm, it's going to need a sounding board of some sort, or it's going to be very quiet. Which may be why the Spanish Inquisition stayed with the old version.
baconbrain, Apr 18 2008
  

       Clarke's "Songs of Distant Earth" described the musical qualities of the space elevator. The cable extended from the planet surface to the space craft, with atmospheric effects causing beautiful sounds. That's a much longer version of this idea.
Amos Kito, Apr 18 2008
  

       This would have unimagineable bass quality.
RayfordSteele, Apr 18 2008
  

       The sounding board could be on the ceiling. Could be the ceiling.
bungston, Apr 18 2008
  

       It sounds like you are all way over thinking this. I think it's a mandoline with special straps that keep it from coming off while bungie jumping.
morganenterprise, Apr 18 2008
  

       This would be a gnarly wind chime.   

       Just where is that gnarly wind when you need it the most...
Canuck, Apr 19 2008
  

       Bellowing through the gnarly plains? I'm glad the voting bakers still fancy a simple physics based idea.. The part I like best about this idea is that, no matter how hard I try I can't figure out what this would sound like, but in my head there is a strongly reverberating vibrato that seems to make sense.
daseva, Apr 19 2008
  

       This is a great idea in all respects except feasibility.   

       Daseva, did you stop to calculate the tension you will need in a 15-foot string to produce an audible note?   

       No?   

       Thought not.
MaxwellBuchanan, Apr 19 2008
  

       [daseva], you ought to ask Galileo's dad. [Link]
Amos Kito, Apr 19 2008
  

       Great Links. Max, who has time to calculate? I'll leave that to the interns. Anyways, the second link kinda bakes this, so it's gotta be possible.
daseva, Apr 19 2008
  

       //Great Links. Max, who has time to calculate? // The people who have time to calculate are the people who make things that work (although the same people generally don't have to do the calculations to see the flaw).   

       Yes, mister Galilei had a room full of weighted strings. He used them because they vibrated slow enough to see them moving.   

       You are about to produce a musical instrument audible only to elephants. Calculate.
MaxwellBuchanan, Apr 19 2008
  

       It's not beyond my comprehension that something out there can vibrate thousands of times per second without disrupting the gravitationally balanced forces contained therein. I don't understand why you are so demanding at this point. Calcs will be produced, as per your request.
daseva, Apr 20 2008
  

       Go for it. Gravitation has nothing to do with it, other than providing the tension. What you're up against here is physics and reality, alas. If your strings are on the order of 15ft long, you'll need a huge tension to make their resonant frequency high enough to hear. To enable them to take this tension, they will need to be very strong which, unless you use unobtainium, means that they have to be quite thick. Sadly, this means that their mass is greater, which means that the tension has to be higher still....you're on a losing battle.   

       I'm not demanding calculations - I'm just trying to point out that you need to engage with reality a little and that, sadly, this won't work.
MaxwellBuchanan, Apr 20 2008
  

       Harmonics. Far back in my wild youth, I found that a fishing line on a hook screwed to a wall outside a house could set up a vibration heard through the entire structure. Pull your fingers down the line, to make the eerie noises. The line could easily be 200 feet long, and dropped to the ground when someone looked out a window. Per [Link], the Earth Harp turns this effect into performance art, with strings five times longer.
Amos Kito, Apr 20 2008
  

       //You are about to produce a musical instrument audible only to elephants.// ...so change the title.
wagster, Apr 20 2008
  

       [Amos] Yes indeed, but those are longitudinal oscillations, not harmonics of a transverse (harp-like) oscillation.   

       [Daseva] Some simple calculations. The frequency of a string is given by:   

       F=1/2L . Sqrt(T/u)   

       where L is the length in metres, T the tension in Newtons, and u the mass per unit length.   

       So, let's assume you have a 5 metre string with a cross-section of 0.25 square millimetres, of high-tensile steel. It will support a load of about 500N, and will have a mass of about 0.002kg/m. Hence, when supporting its maximum load, it will have a natural frequency of 50Hz. Of course you can make the wire thicker, enabling it to support more load, but then its mass per unit length increases proportionately and cancels out.   

       Of course, it will have harmonics, but a string with a weighted (and hence somewhat free) end will not support harmonics to any great degree.   

       So, you are going to be building a large device for replicating mains-frequency hum.
MaxwellBuchanan, Apr 20 2008
  

       We just need carbon nano-strings.   

       If you use Kevlar, you might be able to get up to about 120Hz. Unfortunately, its lower density means it'll carry less kinetic energy when you pluck it, so it'll be a fairly quiet low hum.
MaxwellBuchanan, Apr 21 2008
  

       // You are about to produce a musical instrument audible only to elephants. Calculate. MaxwellBuchanan, Apr 19 2008//
The elephants might like it.
gnomethang, Apr 21 2008
  

       It appears string material and rafter height might be the main points holding this idea back. That and neglecting elephants' musical taste.
daseva, Apr 21 2008
  

       If you added a smaller weight half way along the string, would it double the frequency? If so, could you add weights to divide the string up into 1/4s, 1/8s, etc? Does that only work with relatively slack strings where the force required to move the string is much less than that required to move the weight? I know very little about such things.
marklar, Apr 21 2008
  

       Yes, you can have a weight at any point on the string; the pitch will then be (more or less) what you'd expect from the shorter length of string between the two weights. But then this becomes a complicated way of making a regular harp.   

       I say build it for the elephants.
MaxwellBuchanan, Apr 21 2008
  

       You are saying I can't hang a five pound weight from a rubber band, pluck said band, and hear the note?   

       I would go prove you wrong if it were not such a ridiculous assertion.
GutPunchLullabies, Apr 21 2008
  

       No, [getlunch], I am not saying that.   

       What I said (in words) is that if you have a 15-foot string, you just can't stretch it tight enough to make anything except a very low pitch, before it snaps from the tension.
MaxwellBuchanan, Apr 21 2008
  

       This may help--note the length. "Hanging a B-string from a nail over [a] door, we clamped it at the free end approximately 640 mm from the nail and hung one of our our mail bags off the clamp: Filling the mailbag . . . to a total weight of approximately 8kg, we proceeded to pluck the string and lo and behold a sound not too far from a B was heard."   

       So yes, that worked , but notice that the length was that of a guitar neck, about two feet. As [MaxB] keeps trying to tell you, this idea description specifies 15 feet, and that length would make a super-low note at any achievable tension.   

       Longer is lower, bigger is deeper, heavier is slower. A fifteen-foot string is going to be too low to hear, at any tension that it can take. If you make it thicker, for more strength, it gets heavier, and vibrates slower. It can't work as described--the gods forbid it. A smaller, shorter strappadolin could be made to work, yes. (But it would sound like any other stringed instrument.)   

       Consider this: There is nothing stopping folks from making giant fifteen-foot versions of normal stringed instruments--with frames, bodies and all--or mutant art projects, is there? Except the fact that they wouldn't play anything humans could hear. This is one of those things that isn't being done because it won't work.   

       That Earth Harp (that video was icky) is played by pulling along the length of the string, as [Amos Kito] describes with his fish line. The Strappadolin may be played that way, but the description doesn't say that, it just says "stroked".   

       If it were intended to be played by pulling down along the rosined strings, it would work, [MaxB]'s objections would no longer apply, and it would sound strange. But it would probably not need to be fifteen feet long, and nothing would be gained by having weights instead of a lower frame for tension. (And it would be a lot like an old "panther call" which is a rosined string through a drumhead.)   

       This is one of those things that are just confusingly different enough to seem possible, and vaguely-enough described that folks fill in the blanks in their minds. Then they jump all over the scientist who tries to show the truth. (Sorry, I've been reading Richard Dawkins about religions.)
baconbrain, Apr 21 2008
  

       //gnarly wind chime//   

       I agree. Let's not get plucking fixated. If pizzicato is essential to the idea, have a mic pickup and sound processor (to convert the signal to audible tones).   

       If you're inventing a surreal instrument, high wind passing the strings would make interesting noises. And the rosin-stroked harp or mechanical vibe [Links] are still more ways the Strappadolin could work.
Amos Kito, Apr 21 2008
  

       Actually, only the height of the rafters is specified, not the length of the strings. Perhaps they range from short high notes, all the way down to the elephant levels, providing an immense range of pitches to the accomplished strappadolist. Perhaps a rolling stepladder of the type utilized in awesome old libraries is involved.
GutPunchLullabies, Apr 22 2008
  
      
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