DIGITAL GUITAR AUTO-TUNER PROJECT

What's funny? What ideas?

Usenet messages need to stand by themselves. There is no guarantee that any older messages are available to the receipient. That is why we quote the relevant portions, and post replies after (or intermixed with) the quoted portion. The google usenet interfact is seriously broken, but you can live with it if you follow the instructins below in my sig.

I wish I had thought of that! (You're welcome.)

Jerry

...

Can a piano bridge really twist? One is a long strip glued to the sound board, the other is part of the cast-iron frame. It astonishes me that twist has a significant affect.

Jerry

And now for something completely off-the-scale:

While I'm barely at the "hacker" stage in my DSP knowledge (I'm still working out how modulating a reflected mm-wavelength signal can yield accurate distance measurement over thousands of mm), I have been following the threads in this Subject-line with great interest.

I'm particularly fascinated with the complexity of obtaining a "useful" or "pleasing" tuning for a musical instrument. I hadn't realized that there were multiple "standard" ways of tuning a piano, for example. Thank you all for giving me an excuse to renew my Usenet Lurker's License.

I'd like to ask one question, though, regarding the tuning process for instruments involving mechanical vibration -- not just the ones someone referred to as "plucked" but also percussion instruments and probably others. If, as some have mentioned, the tuning of stringed instruments is made more difficult because people pluck the strings differently (is this the same as "attack". or is that a "keyboard only" term?) and the sound changes over time (decay), why not add a feedback loop into the process?

That is, why not have the "tuning instrument" induce the vibration as well as analyze the resulting sound. A PWM-speed-controlled motor with a _gentle_ off-center cam is probably not the only approach. but it doesn't seem very difficult to do (certainly no more difficult than analyzing the pure sine wave coming from a guitar string ).

Is there a reason that "tuning instruments" (at least, the ones I've seen and the ones discussed here) only analyze sounds and don't attempt to apply controlled signal stimulation? Or is it that such already exist and are simply too expensive for everyday use?

(Whoops! I think I just violated my ULL! Time to re-cloak... er, re-Lurk. )

Frank McKenney, McKenney Associates Richmond, Virginia / (804) 320-4887 Munged E-mail: frank uscore mckenney ayut minds pring dawt cahm (y'all)

-- "Very few things happen at the right time, and the rest do not happen at all. The conscientious historian will correct these defects." -- Herodotus

I read something about a self-tuning piano. It used a magnetic pickup (as for an electric guitar) to sense the frequency. Presumably they excite the string the same way, by driving a current through the pickup coil.

I think that was the piano where all the strings were tuned sharp and to tune a string a current was allowed to flow through the string, heating, lengthening and flattening it. If they used a pickup instead of a microphone then they could tune multiple strings at once without them bleeding into each other. Very clever.

Jonathan

Maybe it would make sense for something like piano, but consider that guitar tuners cost about 20 bucks and can fit in a back pocket. Adding some for stimulation is going to be pretty expensive compared to that, plus as Jerry said, musicians are pretty good at plucking their own strings! Plus, I don't many people that would trust a machine "banging on" their expensive instruments.

I was wondering the same thing.

I read in sci.electronics.design that Jerry Avins wrote (in ) about 'DIGITAL GUITAR AUTO-TUNER PROJECT', on Thu, 28 Apr 2005:

I don't know if it's significant. The sound board bends in all sorts of ways, so the bridge might be moved by notes other than the one under consideration.

instruments.

Somewhere in the attic, I have an oak box with a tuning fork mounted on it. One tine of the fork is driven by a coil and the other drives the button of a diaphragmless carbon microphone that modulates the coil current. Coil voltage is available on binding posts. At one time, it was General Radio's premier 1 KHz frequency standard. Feeding back to a mechanical resonator has been done for a long time.

Jerry

I's have to disagree on the synthesizer. With pitch benders, modulation wheels, breath controllers, etc... the performer has at least as much control over pitch as a tromboner. Leads to some gawd-awful playing too.

Bob

instruments.

I've heard of those "self-tuning" pianos, and from what I've heard, hearing it tune itself is almost a transcendental auditory experience. %-}

World's first "Accutron"! :-)

Cheers! Rich

Electric guitarists have been doing this acoustically since they discovered feedback. I guess there's a whole mystique (sp?) about the process - I think they toss the term "sustain" about. (my brugly other is a professional guitarist, on the side.)

Cheers! Rich

Embouchure, comrades, iron embouchure!

Cheers! Rich

Because the whole point is to get the instrument in tune *as played* by the performer. It is a good thing that the tuning analysis is as passive as possible.

A surprising number of musicians, as well as nonmusicians don't seem to get this: An instrument that's in "perfect tune" can be played out of tune by a bad player (or deliberately by a good player), and a badly-tuned instrument can be played in-tune by a good player. The quality of the overall performance depends a lot more on the player than on the instrument.

I happen to play trombone, which is an extreme example of this, but it applies to all wind instruments and most stringed instruments. A piano (and electronic synthesizer), which I also play, is at the other extreme, being one of the instruments on which the performer has almost no real-time control over the pitch.

-- Dave Tweed

Ever played "Taps" or "Tantara" on a flute? ;-) You really have to overblow it! (joke bait semi-unintended, but noted. ;-) )

Cheers! Rich

Ah. Sounds reasonable. I wasn't thinking of making the entire process automated, but you've given me another obstacle to consider if I ever try.

Yes, my fingers are just a little dylsexic. I'm in an odd industry for someone who was finally permitted to drop Typing in the 7th grade, and (aside from 026/029s) my first real computer keyboard experience was with something called APL with a very "different" keyboard layout.

Frank McKenney, McKenney Associates Richmond, Virginia / (804) 320-4887 Munged E-mail: frank uscore mckenney ayut minds pring dawt cahm (y'all)

-- Everything has to start with fantasy... Knowledge is what you finish up with, if you're lucky, after you've done the hard work -- but the hard work needs passion to drive it. People need reasons to be interested, reasons to be committed, reasons to do their damndest to find the truth. -- Brian Stableford / Dark Ararat

--

I've typed it that way often enough for me to consider legally changing it, but it's in the header mainly as one more obstacle in the way of address harvesting programs.

Frank McKenney, McKenney Associates Richmond, Virginia / (804) 320-4887 Munged E-mail: frank uscore mckenney ayut minds pring dawt cahm (y'all)

-- Q: What are the benefits of speaking to your fans via e-mail? DNA: It's quicker, easier, and involves less licking. -- Douglas Adams / The Salmon of Doubt

--

A trombone will be played out-of-tune by a bad player and will not be touched by a good player. Same thing for the soprano sax and oboe.

In all seriousness, I would much rather play trombone than trumpet (my two main axes) in a large ensemble because it's so much easier for me to adjust the pitch while I play.

Kely

The nice thing about a microprocessor-controlled tuner is that it can be configured to match multiple "good" settings... assuming these can be defined in a way so they can be recognized.

Fair enough, I can see how a violin's "tuning" can be tweaked by minor adjustments of the fingers, and a trombone is also offers a continuous frequency spectrum. Not sure if that makes a self- stimulating tuner _useless_ -- it just says that it's probably not a useful approach for some (perhaps many) instruments.

Ignoring the electronic synthesizer (I just ran across a couple of hex-shafted ferrite-slug-coil tuning wands ), which instruments might benefit? Guitar&fretted, piano&friends... drums? I have _no_ idea how (or if) one tunes a xylophone...

I admit that my interest is a combination of a life as a consultant ("Wait a minute! I can make that much MUCH better!") as well as several frustrating years trying to tune a guitar to match a tin ear (my own). So far, my picture of this thing is a slim wand with a microphone, a string of LEDs (TooLow...TooHigh) and a pager motor with a hard-rubber- coated cam, but I admit I'm probably not going to build it _this_ week.

Frank McKenney, McKenney Associates Richmond, Virginia / (804) 320-4887 Munged E-mail: frank uscore mckenney ayut minds pring dawt cahm (y'all)

-- There is one thing even more vital to science than intelligent methods; and that is, the sincere desire to find out the truth, whatever that may be. -- Charles Sanders Pierce

I read in sci.electronics.design that David Tweed wrote (in ) about 'DIGITAL GUITAR AUTO-TUNER PROJECT', on Fri, 29 Apr 2005:

My colleague, John Bowsher (a physicist as well as a trombonist) demonstrated this to an AES British Section meeting many years ago. Two demos:

- producing a constant pitch note while collapsing the slide.

- producing a swept pitch note with the slide stationary.

I don't really believe it, and I was there!