- #1
Jiminy
Is the "Earth Harp" real (acoustically)?
Has anyone seen this "Earth Harp" guy on TV? He was on "America's Got Talent" a few weeks ago, and I am highly doubtful that this instrument is real. I have a degree in music composition, and I've got several unit of forma instrument acoustics study, not to mention having a firm basis in instruments so I can competently compose for them.
I would like to give a couple of links for reference, but I'm new here and the forum software will not allow it. He has a website and a number of videos on YouTube. His name is William Close, and the name of the instrument is "Earth Harp".
The red flags for me that this is not an acoustical instrument are (in no meaningful order):
1) You can see the strings vibrating. In fact, you can see them wobbling. If discrete vibrations are slow enough to be seen (the resolution of human eye maxing out at about 30 "frames" per second), those vibrations are going to be very low — much lower than the ones he's playing, and if they're lower than about 20 Hz, they're not going to be audible at all.
2) All string instruments require strings which are plenty tight. A wobbly string is just not going to sound.
3) If they the strings were mounted and tensioned properly, and even if they did wake a periodic sound wave, the length and mass of these strings is such that they would, again, vibrate to slowly to be audible.
4) The tension necessary to make such long strings vibrate musically would be considerable to say the least, yet in the guy's booking info page, he lists 6 to 8 small bolts as being all that's necessary for mounting the "sound board" to the stage.
5) Playing a string musically typically requires a displacement that is perpendicular to the string — whether it's bowed, plucked, strummed, or hammered. These create transverse waves. When you hear a beginner violin student play those squeaky tones, he's doing it because his bow is not perfectly perpendicular to the string, so in addition to the transverse waves, he's also producing some longitudinal waves as well. These l-waves are what cause the annoying high-pitched squeaks. Yet the Earth harp guy claims that longitudinal waves are exactly his instrument produces. A slinky is a real world example of something that can vibrate entirely longitudinally.
6) His manner of playing the strings is by rubbing them down their length, again, rather than perpendicularly. I may be drawing a blank, but I can't think of any string instruments so activated. The closes analog I can think of is percussion instrument called a "Lion's Roar", or sometimes just generically it is called a string drum. But these don't sound anything like the instrument in the video, and they use cloth strings, not metal. Moreover, as the fingers are drawn along the length of the Lion's Roar, the indefinite pitch slides in pitch the closer the hand gets to the drum itself. The pitch of the notes on the Earth harp does not change. If the general mechanics of the vibration are the same, the pitch should change, as fas as I can see.
7) On this guy's website, he says that people in the audience claim a wonderful experience when they are in the middle of the sound field created by the supposedly vibrating strings which are run overhead. But strings themselves don't make much sound at all. They transfer their energy to some sort of resonating body which is where the sound comes from. Even if this instrument did work, the sound would come from the sound box on the stage, not directly from the strings overhead.
8) He claims that these Earth harp "installations" turn the performing venue into the instrument itself. For example, when he mounts the strings across some canyon, he claims that the canyon is part of the instrument itself (and he doesn't mean that in the spiritual sense, but the physical one). I don't need to even get into how preposterous this is, much less the notion of playing strings that are stretched across a canyon.
9) On the faster part of the piece that he performs, the articulations are pretty responsive. But in real world acoustics, the larger the vibrating body, the slower it is to speak. That is why flutes are so light on their feet and articulate but contrabassoons are a bit clumsy and indistinct.
10) He's got these wooden blocks mounted to the strings (not mounted at the stopping ends, but mounted within what would be the vibrating body. He claims these blocks placed at different points are what tune the strings. But this can't be. The blocks do not rigidly stop off the string; they just hang there, and all they would do is to impede certain harmonic nodes of vibration, effectively killing the potential for any meaningful vibration. Any yet, the tones in the video are pretty rich in harmonics.
________________________________________
So, am I missing some sort of phenomenon of instrument acoustics, or is this instrument a fake?
My theory of how it actually works is that the pressure he puts on the strings triggers a midi event via some sort of custom mechanism concealed inside the "sound box" mounted on the stage.
Am I wrong? What are your thought about this Earth harp. thing? I'm not emotionally invested in wanting it to be fake, but either it is, or I'm really missing something here.
TIA
Has anyone seen this "Earth Harp" guy on TV? He was on "America's Got Talent" a few weeks ago, and I am highly doubtful that this instrument is real. I have a degree in music composition, and I've got several unit of forma instrument acoustics study, not to mention having a firm basis in instruments so I can competently compose for them.
I would like to give a couple of links for reference, but I'm new here and the forum software will not allow it. He has a website and a number of videos on YouTube. His name is William Close, and the name of the instrument is "Earth Harp".
The red flags for me that this is not an acoustical instrument are (in no meaningful order):
1) You can see the strings vibrating. In fact, you can see them wobbling. If discrete vibrations are slow enough to be seen (the resolution of human eye maxing out at about 30 "frames" per second), those vibrations are going to be very low — much lower than the ones he's playing, and if they're lower than about 20 Hz, they're not going to be audible at all.
2) All string instruments require strings which are plenty tight. A wobbly string is just not going to sound.
3) If they the strings were mounted and tensioned properly, and even if they did wake a periodic sound wave, the length and mass of these strings is such that they would, again, vibrate to slowly to be audible.
4) The tension necessary to make such long strings vibrate musically would be considerable to say the least, yet in the guy's booking info page, he lists 6 to 8 small bolts as being all that's necessary for mounting the "sound board" to the stage.
5) Playing a string musically typically requires a displacement that is perpendicular to the string — whether it's bowed, plucked, strummed, or hammered. These create transverse waves. When you hear a beginner violin student play those squeaky tones, he's doing it because his bow is not perfectly perpendicular to the string, so in addition to the transverse waves, he's also producing some longitudinal waves as well. These l-waves are what cause the annoying high-pitched squeaks. Yet the Earth harp guy claims that longitudinal waves are exactly his instrument produces. A slinky is a real world example of something that can vibrate entirely longitudinally.
6) His manner of playing the strings is by rubbing them down their length, again, rather than perpendicularly. I may be drawing a blank, but I can't think of any string instruments so activated. The closes analog I can think of is percussion instrument called a "Lion's Roar", or sometimes just generically it is called a string drum. But these don't sound anything like the instrument in the video, and they use cloth strings, not metal. Moreover, as the fingers are drawn along the length of the Lion's Roar, the indefinite pitch slides in pitch the closer the hand gets to the drum itself. The pitch of the notes on the Earth harp does not change. If the general mechanics of the vibration are the same, the pitch should change, as fas as I can see.
7) On this guy's website, he says that people in the audience claim a wonderful experience when they are in the middle of the sound field created by the supposedly vibrating strings which are run overhead. But strings themselves don't make much sound at all. They transfer their energy to some sort of resonating body which is where the sound comes from. Even if this instrument did work, the sound would come from the sound box on the stage, not directly from the strings overhead.
8) He claims that these Earth harp "installations" turn the performing venue into the instrument itself. For example, when he mounts the strings across some canyon, he claims that the canyon is part of the instrument itself (and he doesn't mean that in the spiritual sense, but the physical one). I don't need to even get into how preposterous this is, much less the notion of playing strings that are stretched across a canyon.
9) On the faster part of the piece that he performs, the articulations are pretty responsive. But in real world acoustics, the larger the vibrating body, the slower it is to speak. That is why flutes are so light on their feet and articulate but contrabassoons are a bit clumsy and indistinct.
10) He's got these wooden blocks mounted to the strings (not mounted at the stopping ends, but mounted within what would be the vibrating body. He claims these blocks placed at different points are what tune the strings. But this can't be. The blocks do not rigidly stop off the string; they just hang there, and all they would do is to impede certain harmonic nodes of vibration, effectively killing the potential for any meaningful vibration. Any yet, the tones in the video are pretty rich in harmonics.
________________________________________
So, am I missing some sort of phenomenon of instrument acoustics, or is this instrument a fake?
My theory of how it actually works is that the pressure he puts on the strings triggers a midi event via some sort of custom mechanism concealed inside the "sound box" mounted on the stage.
Am I wrong? What are your thought about this Earth harp. thing? I'm not emotionally invested in wanting it to be fake, but either it is, or I'm really missing something here.
TIA