This question has likely been answered before, but what are the possibilities of a bowing model that uses an actual bow on some kind of sensor surface?
written by: bwong
Since Wilhelm is not yet an Eigenharp owner, he is currently unable to post here and has asked me to post this message. For the record, I am in favour of the current owners-only forum access policy at this stage of development, although it does present some logistical difficulties for such endeavours as this.This question has likely been answered before, but what are the possibilities of a bowing model that uses an actual bow on some kind of sensor surface?
We looked at this in passing a couple of years ago. The idea of using one of the Strum/percussion keys on an Alpha or Tau has good possibilities as the sensors there are the same as the main keys, so very sensitive indeed. I could imagine a little thing glued to the top of one of the keys to make this possible, if you fancy some DIY. The main things that you will need to be careful about (and the reasons we haven't yet done anything like this) are applying too much lateral force to the key (more than 2 or 3 newtons is not a good idea) and resonance - bows are designed to make things resonate and if the key (which has a resonant frequency around 1.5KHz in free air) starts to resonate then I have no idea what your output would look like - the sampling frequency is around 2KHz and there is no real filter, so you need to strong aliasing effects if this happens.
I thought a bow with a slippery plastic tape, maybe PTFE or Nylon might be interesting, something with low friction so that its not prone to resonance.
Please bear in mid that we don't warranty the instruments for this kind of experimentation, but if you do decide to try it I'd love to hear how you got on.
John
Thank you for this response John! Would you consider this type of lateral force and resonant vibration too extreme for experimentation with the standard Eigenharp keys?
Yes, probably. They have a lower (by a factor of two) spring constant than the larger keys and will therefore be more susceptible to damage. It would be down to whether or not you could make a bow/keytop system that had a low enough friction to keep the lateral forces withing acceptable limits, which would depend on the height of the system, and certainly in the 1-2 Newtons range I should think. This seems like a fairly difficult proposition to me, as musicians are prone to get quite physical with their instrumnents in the heat of performance.
The alternative would be to glue something to the top of the key or opening that also restricted it's physical movement to acceptable limits, and perhaps increased its lateral spring constant considerably (and could also, if it were a suitable material, provide resonance damping). We have thought about quite a few things in this space and it seems likely that a DIY, slightly bodgy approach could yield some interesting results (providing that you don't mind voiding your warranty). Our problem is making something that is lovely looking, tough and reliable and manufacturable at reasonable cost - that is always a tough set of requirements to meet.
I have imagined several ways this could be interesting. With a Pico the possibility of using the two keys currently used for scrolling to be 'bow receptors' (it's be like having a two string violin, as much as one gets on the wooden one) and the rest for fingering while mounting it in some way on a chinrest (like a violin) seems attractive and could be a lot of fun. With the Tau and Alpha the percussion/strum keys are crying out to have an addon to enable this.
I have an offer to make here - if there are any students out there (preferably a student doing a thesis project or related project structure) who want to have a go at trying this (a violin style Pico) I'll donate an ex demo Pico in their direction to break (well hopefully not) as long as they commit to put the results of the experimentation fully in the public domain. And if someone who's not a student wants to have a go we'll sell you a used Pico for a low price on the same terms, and throw in some spare key frames so that you can break a few on the way (although they are a bit of a pain to change on the Pico, it can be done).
John
Well, FWIW, Some time ago I tried a (new, resin-free) horsehair bow on the top lower Alpha key. It actually worked somewhat if you place the relevant 'corner' of the key under the bow for each direction (which leads to a great deal of flailing about).
I suspect it could be mastered and, without resin, this does not seem create a slip-stick... you are basically just pushing the key.
Personally I like'd Geert's tiny finger violin demo in SF; reminded me of that old joke where one crosses their fingers with a bowing motion but a bow id showier.
In the event I've really stuck to breath for bowing having has little success with the other methods.
It would be really interesting to see what comes of a proper pass at bowing
:-)
m
This is a generous an open-minded offer John! I am certainly interested, though not a student, and would be glad to purchase a used Pico and participate.
This leads me to a related issue. Much of my interest in this topic has been precipitated with my discussions with instrument innovator and bow materials experimenter, Wilhelm Matthies, who I believe can contribute to this discussion and research. Also I would very much like to be able to relate your generous offer to the Csound list, where many students and professors would be made aware of it. Having this forum open to the public would obviously help in this regard.
Brian
Since Wilhelm is not yet an Eigenharp owner, he is currently unable to post here and has asked me to post this message. For the record, I am in favour of the current owners-only forum access policy at this stage of development, although it does present some logistical difficulties for such endeavours as this.
Brian Wong
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Hi John,
I see that your company briefly considered making the Eigenharp bowable with a physical bow other than with finger movements.
I understand that currently there is a key that could be experimented with on a Pico. An immediate problem is that the key is sensitive to lateral force and resonance. I understand that your interest in this matter is re-opened.
I have thought about bow development recently, what bowing means and what it can do for performing musicians. I believe that I can contribute to the advancement of this aspect of the Eigenharps.
I also see that you posted more thoughts about bowing and that you are interested.
Bowing with your finger is like painting with your finger, bowing with a physical device is like using a brush, ie., with more precision and specific to a particular task. One thing that is needed on the Eigenharp instruments is the ability to bow with the level of precision and expressivity of a physical instrument. Being able to bow with your finger is a good, but only a first step forward.
I and Brian Wong have several proposals on how to deal with the prospect of bowing with Eigenharps.
Bowing sensor
The sensor would need to be static electric free, and isolated via a rubber-like gasket so that no vibrations interfere with the other keys on the instrument. The bow sensor needs to have the toughness of a physical instrument. The ruggedness would allow players to feel free to be fully experimental and to have a wide range of sensitivity to be able to work towards mastery in the same way as traditional instruments allow for this to happen.
I have a suggestion for a bow sensor and Brian Wong has one too.
I propose to make the sensor concave formed, like a u shaped trough.
The u shaped trough would be at a 90% angle to the Eigenharp’s body, so the bowing would take place within a groove. It would be pressure sensitive, the assignable x axis would be on the upper half of the groove, the other side would be the assignable y axis.
This scenario would allow for bowing the x and y axis simultaneously. I imagine that there would be five of these for the Alpha and Tau models and two for the Pico in an arched arrangement.
Brian Wong proposes that the sensor should be designed like a trackball. Flat edges of a partial sphere would limit movement to a safe distance, and allow for minimal alteration of current key design. The top edge of the key would be convex to allow for bows with a concave channel to pass over the key.
I have two basic points here. Several designs could work, but in any case, the bow sensor needs to be as rugged as playing on a cello or even on a drum. This leads to my next point.
Bows would not be bows in the traditional sense
Traditional instruments from the violin, erhu and rebab families use horsehair and rosin to cause vibrations. The rosin is necessary as the string needs a medium to smoothly vibrate, but also because the string is a metal, nylon or silk string.
Horsehair and rosin is not appropriate for the plastic Eigenharp keys.
The kind of bow I propose can be imagined like a bar with multiple planes. I imagine each plane of the bow with a different degree of surface pattern in degrees of smoothness to roughness, so that the player has a direct and immediate control of the textural quality of the sound. So it is the character of the texture, and the rate at which it is played which contributes to the sound quality of the instrument. A finer texture=finer wave form, rougher texture=rougher wave form, all still modifiable with the software, but allowing for direct, physical control from the player.
This is where the skill of the player will come into play as in playing a traditional instrument, the player has to learn how to skillfully move the bow with precision, but also opens the door for independent developers to create unique and/or manufactured bows.
Hard wood versions could be made. Most likely a plastic would work better as precise textures could be laser cut, blade cut, molded or pressed. The plastic would need to have anti-static properties. The number of planes that would be most practical, and how long the bow should be would need to be experimented with, but probably close to current bow lengths would work.
A proposal to develop bowing with a Eigenharp Pico
I propose that an industrial design student work with Brian Wong as collaborators.
Brian and I would work with the student to develop the geometric form of the plastic key such that it would securely fit into the existing slot but also accommodate physical bows.
I would help in selecting materials that would be suitable for the bow and help develop how it would be textured and test it out as a performing musician. Brian Wong would also test which plastic key forms and which bows would be most suitable work and work on programing with EigenD/Belcanto programming.
I am willing to purchase a used Eigenharp Pico in exchange for doing this research as you mentioned on May 11.
Please contact me via my SoundCloud email as to how I should purchase such a used Pico.
Listen to music that I have made with a kokeka, an instrument that I invented and play with a variety of bows, short and long.
http://soundcloud.com/wilhelm-matthies
See short pick-bows that I have invented to be used with the kokeka and any acoustic stringed instrument but for electric and acoustic guitars in particular:
http://www.flickr.com/photos/wbhmatthies/sets/72157626300790645/
If you look at my track record you will see that I am very experimentally oriented. I am ready to purchase a used Pico with extra keys to develop the bowing capacity.
Wilhelm Matthies
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