Preference: Does anyone actually even want "perfect" linearity?

I'm not sure what it would feel like to play a theremin with perfect linearity, and even if I did have such an instrument the linearity would be thrown off immediately because I move when I play.

What I found after playing the theremin for a couple of months (back in '96) is that maximum dexterity of the pitch hand is achieved when the pitch hand is as close to your body as possible. Try signing your name while holding your pen at arm's length and you'll see what I'm talking about. So I devised a technique where the thereminist adopts a kind of "Tai Chi" stance with one foot to the side and in front of the other which allows the body to rock freely and easily back an forth (toward and away from the pitch antenna) without changing the position of the feet. This is a radically different approach from that of Clara Rockmore, where the thereminist retains a rigid "at ease" position with feet parallel to one another like a capital letter 'A'.

One of the by products of the Tai Chi approach is that the linearity of the instrument changes depending on your body threshold (how far your body is from the instrument). Perhaps this has bothered me less than it might bother some people because I have six theremins (including two RCA's) and their linearity and various configurations are completely different from one another. I am constantly having to adapt depending on what instrument I am playing. It's a bit like comparing race cars. Each has its own individual "feel" and way of handling, and it is up to the driver to find the comfort zone. 

You have to enter into a sort of free-flowing symbiotic relationship with your theremin - a relationship in which shifts in the parameters of your instrument are influenced by YOU, and YOU adjust your movements according to those parameter shifts. It's a kind of dance.

My main problem with most of the precision theremin playing I hear from accomplished thereminists is that there is no fire or passion in their playing. They have worked like MF's simply in order to be able to play on pitch. Playing on pitch is not the goal of theremin playing, it is the starting point for something much greater. 

I don't believe that perfect linearity is going to help one single bit in the pursuit of this greater goal. 

"N.B. I can’t really imagine playing a fiddle whose note spacing was linear!"  - RoyP

Perhaps you might have welcomed it when you first started on the fiddle?  I've played the guitar since 13 and I'd take a linear fretboard in a second.

"My main problem with most of the precision theremin playing I hear from accomplished thereminists is that there is no fire or passion in their playing. They have worked like MF's simply in order to be able to play on pitch. Playing on pitch is not the goal of theremin playing, it is the starting point for something much greater. 

I don't believe that perfect linearity is going to help one single bit in the pursuit of this greater goal.  - coalport

Maybe their brains are too occupied with trying to maintain pitch on a non-linear Theremin to take things to the next level expressively?  Kind of like when a person simultaneously sings and plays accompaniment, their performance is reduced to a subset of their full non-multitasking ability.

dewster wrote: Maybe their brains are too occupied with trying to maintain pitch on a non-linear Theremin to take things to the next level expressively?

Preoccupation with pitch is undoubtedly part of the problem, but I think there's more to it than that. The big question is: WHAT ARE THE ESSENTIAL ELEMENTS OF FIRE AND PASSION IN THEREMIN PLAYING?

What are the "nuts & bolts" of a truly sensitive and moving performance?

coalport wrote: One of the by products of the Tai Chi approach is that the linearity of the instrument changes depending on your body threshold (how far your body is from the instrument).

But it changes it in such a way that it (at least partially/approximately) compensates for the non-linearity of the instrument, right? Theremins have the higher tones more close together, but when you get closer to the theremin to play them, that spaces them out. So I guess it's a way to get closer to what Randy George called a "linear interaction".

Perhaps you might have welcomed it when you first started on the fiddle?. – dewster

Perhaps, or perhaps not. I just accepted the instrument and it’s foibles and got on with it.

In fact I can now see the advantages of having a progressive non-linearity in the violin: without it, the note spacing at the bottom end would be smaller so the 5 octaves could fit onto the fingerboard or the fingerboard would have to be significantly longer or another string could be added but then the fingerboard would be wider and the strength of the notes produced on the bottom/top strings may be compromised. I know though that 5 string violins do exist.

There are many people (myself included) who would maintain that the evolved design of a violin is as near to perfect as it will ever get.

I'm not an expert in physics so maybe some of the more knowledgeable users can correct me if I'm wrong. But as far as I know, the reason why instruments where strings are manipulated directly by the performer (like guitar and violin) are nonlinear is a purely physical reason. The relation between the length of a section of string and the note it produces is not linear, and there's nothing you can do about that except for not requiring the performer to manipulate the length of the string directly when playing (as in a piano).

Instrument makers worked with that reality and came up with great designs for instruments that work under those conditions. I don't play the violin but I imagine a linear violin wouldn't be desirable, because the design of the instrument evolved to work well with nonlinearity, and surely after so much evolution it should be almost perfect under those specific conditions. But what would violins look like in an imaginary world where the relation between string length and pitch were linear? They would probably have evolved differently and look differently in the first place, due to the different physical conditions, and the playing technique would also have evolved in a different way. Would such imaginary instruments be easier to play? Who knows, this is just an abstract rambling... but I don't see why they would be harder.

In the case of the theremin, we don't have such stringent physical restrictions (as some theremins are more linear than others, and the experts in this forums talk about arcane coils and other artifacts that alleviate or change nonlinearity), so we are not necessarily limited to designing the best instrument for a given fixed mapping between physical space and pitch. Here, changing that mapping is not an abstraction, we can actually do it!

AlKhwarizmi: Theremins have the higher tones more close together, but when you get closer to the theremin to play them, that spaces them out. So I guess it's a way to get closer to what Randy George called a "linear interaction".

If I have understood Randy's post correctly, he does list a number of variables involved with "linear interaction" but he is looking for a fixed and stable linearity while I prefer mine to be changing and dynamic. 

When I first began playing the theremin, I was learning on an old Big Briar Etherwave and the linearity was extremely "pinched" in the upper octaves (EW's have greatly improved since). Accurate control was impossible unless, as you pointed out above, the body of the player was shifted very close to the pitch antenna. The increase in capacitance within the playing arc resulted not only in wider spacing between the notes, but an increased range as well (roughly another major third).

At the time, the only pieces I was playing on the theremin were transcriptions of soprano arias from operas. I was not particularly interested in using the instrument for anything else. In order to put a sense of drama and emotion into these transcriptions, I had to be able to control the rate and depth of my vibrato the way really fine classical singers do, and it didn't take long for me to realize that such control was much easier when my hand was close to my body.

So the whole body shifting technique had three advantages: I had better linearity in the upper octave, a slightly increased range, and better control over the movements of my hand & arm. 

For me, the theremin is an electric classical singer. It used to be an electric soprano, but now that we have the Electro-Harmonix TALKING MACHINE, it is also a remarkable, although slightly over-used, electric tenor. Of all the musical instruments available to musicians, the human voice (the "vocal instrument") is the only one you have to be born with if you want to play it. Anyone with the time and a little musical aptitude can learn to play the cello or the flute or the piano, but a heavenly, operatic voice is a natural gift that very few people have. If you ain't got it, yer outta luck.

ENTER: the theremin

For anyone who wants to explore the classical vocal repertoire but who is unable to sing, the theremin is the perfect solution. No other instrument sounds like it, and it possesses an uncanny human quality that can be found nowhere else. The downside is that it is by far the most difficult instrument to play that has ever been conceived. 

"It is much more difficult than the violin which I played for years." Clara Rockmore

"It is much more difficult than the violin which I played for years." Clara Rockmore

This citation finally makes the whole discussion obsolete. Why not simply accept this and other statements of the "Grande Dame du Theremin"?

a) It's extremely difficult to play, even more than the violin

b) It should never be one's first instrument and preferably one should have studied the violin before

c) First, you must have music in your soul

My conclusions  (always talking about precision playing of classical music):

- The theremin is not an instrument for everybody, but only for a very few people which have a special talent and fulfill strong prerequisites.

- The best engineer without being at the same time a trained musician (preferably a string instrument) will never be able to design a very good theremin.

- Since there is not (yet) a commonly established and standardized method and playing technique, a theremin designer has to cooperate constantly with a wide variety of professional and semi-professional theremin players in order to not produce "besides" the market.

- Technical data and considerations become totally unimportant in the moment when the musician starts playing the instrument. Either they feel that the instrument is suited to play a piece with the desired expression or it is not. If not, the engineer must be enough musician to understand the critics of a non-technician and to translate them into electronics, so that the musician will finally be satisfied.

- Musicians don't care about inductances, coupling factors, air or ferrite coils, armstrong or colpitts oscillators, etc. It's the musical result which interests them.

- "The execution must not be a victim of the technique" (Herbert von Karajan)

"The best engineer without being at the same time a trained musician (preferably a string instrument) will never be able to design a very good theremin." - Thierry

I must disagree completely with the above. The designer of the Tvox (used by Lydia) is not a musician - he is a competent engineer who had a competent thereminist to advise him, and he designed a great theremin.. I remember you lusting after the Tvox, and for good reason - It is certainly the most playable theremin I have ever come across.

I get REALLY piss*d off when statements like this are made as fact - The statement is, in fact, the creation of another myth to add to a long list of "theremin myths" which are sucked out of thin air, have no basis and are just plain WRONG, and are created soley to serve the interests their creator/s.

What the statement declares, in bold red, is this:

"Fred (and other theremin designers who are not musically trained like me) is not a trained musician, therefore it is impossible for him to design a very good theremin"

 - RUBBISH !!

Was Bob Moog a "trained musician" ? What about other very good theremins, were they all designed by "trained musicians" ?

In fact, apart from Lev, can you name any "very good theremin" designed by a trained musician? (not saying there arent any - but I cant think of any).

I had piano lessons for 6 months when I was 6 - does this qualify me as a "trained musician" and if not, what exactly does?? (perhaps my 2 years learning to beat a Djembe ?)  LOL.

By your declaration, Bob Moog never designed any "very good theremin" - I DISAGREE!

IMO, the important facts regarding theremin design are competence in electronics and physics, good hearing, and the intellegence, perseverence and ability to understand concepts outside of ones specialist area (as in, if one doesnt understand what the musician wants, keep communicating and researching until you really do understand what they want - and explain to them your understanding of what they want until your understandings are in harmony... This principle applies to all clients - When designing lab gear for a microbiologst, one needs to understand their requirements, which may involve extensive research and learning - This is how R+D works! Communication! )

Fred.

"I don't play the violin but I imagine a linear violin wouldn't be desirable, because the design of the instrument evolved to work well with nonlinearity, and surely after so much evolution it should be almost perfect under those specific conditions."  - AlKhwarizmi

Try turning the world on it's head for a bit.  Imagine our ears perceived linearly spaced pitch intervals as linear rather than logarithmic changes.  The violin might remain as it is, almost perfectly evolved, but we would play it a bit differently.  The fingering and distances one used at the nut position would work anywhere on the fingerboard.  The nut position would be more cramped though, and it's range would probably change.

Anyway, when the controller is separated from the sound generator, as with the SynthAxe MIDI guitar, many performance input parameters that were previously strictly dictated by physics are then suddenly at the whim of the designer, and what you usually see is linearization of the pitch control interface.  As you mentioned, piano is another good example, where the pitch is made discrete via separate strings for each note, and the controller is then implemented as a linear mechanism.

Also, why are there EQ coils in many Theremins?  They're there to expand the pitch field away from the antenna, giving a somewhat linear seeming middle playing field.  I'm kind of new to Theremin discussions, but other than coalport's argument (it helps control vibrato because the hand is near the body - and his body movements looks pretty dramatic in the videos!) I don't hear of people removing coils to get less linearity.