The pitch preview display -- how it should be

Posted: 4/1/2013 1:28:16 PM

From: Northern NJ, USA

Joined: 2/17/2012

"But I still doubt the usefullness of visual pitch preview - particularly if overcomplicated."  - FredM

With that caveat I agree.  But a minimalist display can be really useful IMO.

With one LED per semi-tone and PWM, I find it easier to play the "notes" located "between" the LEDs, i.e. two LEDs lit to approximately the same brightness, rather than most of the brightness on one LED.  I don't have to constantly watch it like a hawk to play, but I do find myself checking it for reference and using it much more than anticipated. 

It needs bi-color and some kind of octave display, still not sure if I'll go staggered circular or staggered linear for the note display.  Circular makes the most sense, but linear might be easier to read.

ILYA, I suggest you stagger every other LED so as to take advantage of the eye's ability to discern shapes, and maybe work bi-color into the staggering scheme (this is my plan).  I'm not going to use any particular key, the semi-tones will be green / red / green / red / etc. (two LEDs lit) with red+green=yellow (single LED lit) in between notes.  No stepping behavior or thresholding, just continuous PWM.

Posted: 4/1/2013 3:01:34 PM
RS Theremin

From: 60 mi. N of San Diego CA

Joined: 2/15/2005

Hi All,

Back from Tahoe doing a little snow skiing. I always need to rest at least once on my way down the mountain. I meet this gentleman at about 12,000 ft from Austria; he spoke like our ex- CA Governor (Terminator). He was eighty years old! We were going to go to the lodge for drink and amazingly I could not keep up with his slick style of effortless skiing!

A veteran never needs to brag as the talents not apparent at first will be revealed.

Below is simplicity in a tight package,10ms (.1 sec) latency. I have posted this before and worth doing again. Don Lancaster said in 1980: “If it takes more than three chips to build, go with software”.  Download  345kb  Freeware

I can't imagine anyone watching this display when they perform but it is dead on accurate for knowing where you are in any given moment. On my large TV flat screen color organ display I am designing for my personal use, I was going to have this in the upper corner as I never leave home without it.

The theremin tone is so clean and steady at the pitch preview this program has no trouble giving instant virtual results. This is too slick!

Actual Size
Pitch Tuner for Theremin


Posted: 4/1/2013 3:13:51 PM

From: Theremin Motherland

Joined: 11/13/2005

Gentlemen, I posed the question not about the advisability but about ergonomics. Linear vs circlular.

Linear is easer to read, as dewster mentioned, moreover it correlated with hand movements.

Circular is more consistent with the philosophy of music.

coalport, reffering to face of SABINE ST-1100 AutoTuner:

what is the sacred meaning of red C and F?

dewster: Use PWM to show where you are between notes
yes, ofcourse.

Posted: 4/1/2013 7:40:24 PM

From: Northern NJ, USA

Joined: 2/17/2012

"what is the sacred meaning of red C and F?"  - ILYA

Weird.  And why are FLAT and IN TUNE yellow but SHARP red?

Posted: 4/2/2013 12:29:20 AM

From: Canada

Joined: 8/1/2008

I just looked at my old Sabine tuner, which is a much older version than the one in the photo above, and there are differences. All the lights on mine are RED with the exception of the "in tune" light which is green. Not that any of that makes a difference. As far as I'm concerned the device is useless for the theremin and I suspect all other visual pitch devices, whether gauges or idiot lights, linear or circular, are useless as well.

Perfect pitch will not help you find your starting note in the absence of sound. Clara Rockmore had perfect pitch and if you turn your stereo up you can clearly hear her searching for her note before she begins to play. 

Posted: 4/2/2013 4:29:37 AM

From: Eastleigh, Hampshire, U.K. ................................... Fred Mundell. ................................... Electronics Engineer. (Primarily Analogue) .. CV Synths 1974-1980 .. Theremin developer 2007 to present .. soon to be Developing / Trading as . ...................................

Joined: 12/7/2007

"Perfect pitch will not help you find your starting note in the absence of sound" - Coalport

Thanks for clearing that up, Peter!  I was under the belief that "perfect pitch" was absolute - As in, someone with perfect pitch would be able to hum a perfect A440 when asked to.... Thinking about it now, thats such an absurd idea I wonder how I didnt see it for the baloney it was ;-)

So .. Perfect pitch and perfect reletive pitch are one and the same.. If you hear a note, are told its a "C" one can hum the C Major scale (provided you know its sequence) based on the given note... In fact, you dont need to know its a "C" - You can start at any note, even if not "on key" and produce any scale or tune or whatever reletive to that..

And if you can do the above, and your reletive notes are spot-on when you hum or play a theremin or other instrument without visual or tactile feedback, you have "perfect pitch" (!?)

Hey, that makes me feel a lot better ;-) .. And a bit less like I am missing out on some rare ability only a few lucky people posess.. LOL ;-)


Re visual feedback... Humming or singing or whisteling etc (your voice) must surely be classed as an instrument without any visual feedback - even less feedback than the theremin! - but those with a good sense of pitch can do this without any need for visual guidance... Sure, the voice is probably the easiest instrument to control, the one we have the most intimate connection with, and it gives me sensory feedback which is a kind of "preview" - one knows by the tension on the vocal chords exactly what tone will come out before you make a sound (I find this less true when trying to whistle)

Which kind of re-inforces Thierry's comments me thinks - I had wondered whether his arguments regarding trombone, violin, odes was as valid as it first appeared, thinking that perhaps the not-obvious-but-perhaps-still-present visual feedback was important.. But thinking about the voice, I think he is completely correct.

One needs to "know" what the correct pitch should sound like in order to produce it.. And if you know it, but cannot produce it, the problem is with the control mechanism or the sensory feedback... And with audio preview from the theremin, you have this feedback - so if you still cannot get the note, the problem is with the control mechanism...

But it is only if you dont know the pitch you need to play (you cannot hear it in your head, or tune your vocal chords to it) only then, I think, could visual guidance be useful - "The display shows that I am at C and the next note I need to play is G, so I need to go closer" - And I think most people who play the theremin have gone beyond that level in a few weeks... Or else they just dont have what is needed to play this instrument melodically and certainly dont have what is required for precision playing...

The only practical reason for pitch display that I can see is therefore if, for whatever reason, one refuses to have audio preview - Then visual feedback MIGHT help to avoid fishing for the correct note when bringing the volume up from silence.. In this regard, I think the visual feedback from the trombone/violin/odes and the sensory feedback from the voice may be an advantage, and some form of visual 'cuing' added to the theremin mignt help.

I think that those who "dont have what is needed to play this instrument melodically and certainly dont have what is required for precision playing" can still have fun with it and use it musically or creatively - Some of the most interesting theremin music I listen to (and it is music!) doesnt have any pretention about trying to comply with musical scales or "normality".. And I doubt if these musicians would have any interest in visual pitch display... And I have no idea if they can hear their "target" pitch in their head before they play it, or if their music is controlled by other forces ;-) .. All I know is that I enjoy listening to it (in small doses ;-)


Posted: 4/2/2013 10:05:40 AM
randy george

From: Los Angeles, California

Joined: 2/5/2006

The first question for any chromatic visual indication of pitch... what is going to be used for? Finding a note from silence?  in that case, ILYA your design is great.  However, if a visual indication of pitch is intended for improving pitch location skills for bettering the theremin playing experience, it absolutely must be high resolution with a very fast refresh rate, or else it will not be useful.

Peter said:

"The visual preview may work for those who are playing at the beginner level, but it is totally useless for advanced precision thereminists."

Peter, maybe you meant to say, " 'Slow' visual pitch preview is totally useless...  I wish there could be something faster, then I might change my mind." ... right? :)

The following is my opinion:

The best real-time software solution for display of pitch:  MIDI Merlin. yes, this is a biased opinion. 

I'm not sure what the exact latency is. I'll have to measure it at some point, but sampling rate is fast enough that vibrato oscillations are clearly reflected in real-time... and that should be fast enough for anyone requiring a visual aid.

MIDI Merlin's input sample rate can also be adjusted up to 96KHz if anyone wants even higher resolution. but it's at the cost of CPU cycles. The current note is reflected in the Tuner window and also on the 6 octave Keyboard Feedback window. the sub bass registers often give fluctuating readings, but everywhere else, is very accurate.

When I used MIDI merlin as a pitch feedback tool, I magnify the Tuner window in Mac OS to and it can appear large enough to see the note name and tuner meter.  It's unfortunately difficult to see from far away, without magnification or good eyesight.  I may make an option in a future version to make the tuner become full screen.

While these tools exist, I've gotta say, as a thereminist that has created my own tools and has benefited greatly from them, I do not recommend visual pitch aid to be used at all times.  It is best used as a tool improve relative pitch acuity and become aware of nuance and stability with subtle body movements... I'd say mostly to build an internal sensitivity to harmonic interval widths(in equal temperament tuning). It has nothing to do with being a substitute for perfect pitch. I think perfect (or absolute) pitch is useless in theremin playing. I know a few theremin players that have the "gift" that have said the same and or have demonstrated that the ability does not help make the theremin any easier to play.


Christopher, in the documentation page for that Tuner app you posted, it mentions the sample slice is 1/10 of a second.  that would be 100ms right?  I downloaded it, tried it and it felt more like 100ms. 

Posted: 4/3/2013 11:18:55 AM

From: Canada

Joined: 8/1/2008

Randy rote: "Peter, maybe you meant to say, " 'Slow' visual pitch preview is totally useless...  I wish there could be something faster, then I might change my mind." ... right? :)"



Well....actually.....NO. What I meant to say was exactly what I said. The speed - or lack thereof - is only one of the problems with the visual pitch preview. The other problem has to do with divided concentration and the perils of multitasking.


One of the reasons precision thereminists have that far away, blank look on their faces when they play (something we don't see so much with other musical instruments) is that they are so focused on the difficult task of finding and "trimming" pitch every second, that they are more or less oblivious to other things going on around them. They are totally concentrated on SOUND and coordinating the movements of their hands and arms with the audio input from their monitor. The motor and premotor cortexes of the brain are engaged to the max, and coordinating with the temporal lobe (where hearing is processed) and there is no grey matter left over to focus on visual input and still perform at, or close to, 100% efficiency.


When I played the theremin using a visual preview, I found the split concentration very annoying. The primary visual cortex is in another part of the brain altogether (the occipital lobe) stuck waaaay in the back - much too far to go and get home with the pizza in time for supper!


A very good friend of mine is a professor of neurology at McGill University in Montreal, and I have discussed this with him. What thereminists are dealing with is a form of multitasking. Does multitasking slow down brain response time? Absolutely! And the more tasks we add on, the slower we get. There are all sorts of articles on the internet related to this phenomenon, but basically when we try to do more than one thing at a time, or try to process sensory input of different sorts simultaneously, what our brain does is jump rapidly back and forth between the various jobs we expect it to do.


An audio pitch preview puts all the information into one, single, acoustic basket and makes it much easier to sort out. O.K., so you look a little blank and zonked out, but at least you're on key, and coming in on time! The brain is already directing hand/ear coordination. If you add a variable visual component to that, you slow down significantly. Yes, there is a visual component in playing the piano or the organ, but it is not variable. Your keys and organ stops are not shifting or changing in any way like the blinking lights on a visual pitch preview, or the swinging needle of a frequency gauge.


Professor Earl Miller, a neuroscientist at MIT said of multitasking, "People can't do it very well, and when they say they can, they're deluding themselves. The brain is very good at deluding itself."

Posted: 4/3/2013 1:40:39 PM

From: Northern NJ, USA

Joined: 2/17/2012

"The other problem has to do with divided concentration and the perils of multitasking."  - coalport

I believe at least a portion of multitasking brain overload issues are associated with how we learn particular tasks.  For instance, from the beginning I learned how to simultaneously sing and fingerpick/strum the guitar, so I can do this moderately well without too much interference between the two.  But I've met people who learned guitar first and wanted to add singing later and it didn't work out so well - it seems some of the singing part of the brain got co-opted for guitar playing.  My wife has seen this in some piano players as well.

Posted: 4/3/2013 4:57:15 PM

From: Canada

Joined: 8/1/2008

If you are able to sing and accompany yourself on piano, guitar, harp, or some other instrument, the degree of technical difficulty of what you are able to do on the instrument will inevitably be compromised if you are singing as you play.

One the other hand, if you are playing something really difficult and intricate, your ability to sing with all the power and/or expression you would like to put into it, will be compromised.

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