Tap Tone Tuning of the Old Masters

[lyndon]

well here goes, ive mentioned this tuning method several times on this forum, but never in its own thread, this first came to my attention while working for a 90yr old viola maker, christian martin kob(marty) in southern california in the 80s, we found that usually only on our best violins and especially the older ones, there was a pattern of noticeably different tones being produced when we tapped on violins in different areas, for instance the lowest tap tones seemed to come from the bottom left of the top, and much higher ones from the top left or right, depending on the maker, in addition the two contact spots of the bridge feet seemed to be markedly different tones but in tune with each other, and we found on well tuned violins the back was tuned almost the same but a semitone or full tone higher in pitch than the tap tones on the front

i wont bore you with the details but give you info so you can tap on your own violins and make your own conclusions.take a picture of a violin top, then draw or imagine 4 large circles that pretty much cover most of the top and bottom of the violin, following on their ouside the curve of the outside edges of the violin, these circles should meet or barely overlap in the middle, and come no where near the bridge, so you have a large circle encompassing the bottom left of the violin, another one encircling the bottom right, one for the top left and finally one for the top right

then you are going to tap your knuckle in the centre of each of the four circles, so your tapping in the centre of the bottom left, then the centre of the bottom right, then the centre of the top left, then the centre of the top right(sometimes these last two are tuned back the front, right then left)

on a tuned instrument, if you can hear this, youre going to hear tuned intervals starting with the lowest note and going higher in fifths(or some other tuned interval)ive seem perfectly tuned instruments where bottom left is G, bottom right is d, top left is a, and top right is e1 just like the four strings,then when you tap on the back, remember its a mirror image so you tap bottom right, then bottom left, then top right, top left often its g#,d#,bb,f, or A,e,b,f# a semitone or tone above the top

much less important than which notes the wood is tuned to, or possibly even what pitch the tones are tuned to, is how well the different tones blend together to be in tune and harmonious with each other. a well made instrument thats not tuned may sound quite good indeed but i cant help but think tuning it would have made it better, and probably couldnt have made it worse

in addition to the tap tones of the four "corners" the left and right bridge feet positions and the soundpost contact spot on the back also seem to be tuned, so there are 6 tuned tones on the top and 5 on the back, and maybe others ive never heard of on the ribs etc.

end chapter 1

[lyndon]

i forgot to add im talking about testing the tap tones on a finished, varnished, assembled instrument, whether it is strung up or not makes no difference to the four main tap tones per plate, but it is hard to test the bridge left and right tap tones with the bridge on, and yes the soundpost should be installed as it can make a difference

for the top were basically dividing the top into 6 major areas, left and right bottom, left and right middle, and left and right top and tapping basically smack dab in the middle of each of these areas

i should add you can test and even adjust externally the tap tones on an assembled white violin, but you have to compensate that the varnish is going to raise the tones about a semitone when finished

[fiddlewallop]

Lyndon, What is your criteria for "old violins"?

17th, 18th, 19th century?

[lyndon]

from my survey this technique shows up frequently from 1700? to 1900, with a few hang ons after 1900 still using it, ive had a 1937 eh roth in the shop that appeared to be tuned, but definetly you dont see the tuning on low grade 20th century stuff

as most baroque violins underwent conversions including installing longer, heavier bass bars sometime in the 1800s, it seems to me the people doing the conversions would have been well aware of the tap tuning method and also understanding that without fine tuning, the new bass bar would throw things off, also the pitch had changed and was somewhere nearer to a440,

tap tuning a violin only involves removing miniscule amounts of wood, so when i see a 1700s tap tuned violin, the tuning may not be 100%original to the 1700s, the tuning may have been updated and modified in the 1800s. also ive seen 1700s violins regraduated in the 1800s still have their tap tuning, presumably from the regraduater

[MikeC]

Have you encountered any really good violins that did not have that type of tap tone?

Do you have any advice on how to 'hear' the tones? I'm not tone deaf, I can self tune my guitar and match notes perfectly but when I tap on my fiddle I can't hear notes. It just sounds like wood being tapped. Maybe I need to get a wood xylophone for comparison.

[jacobsaunders]

would you be upset, Lyndon, if the forth possibillity "id rather tune out anything lyndon says" comes out on top?

[Ken_N]

Ok, I've only held 2 or 3 real instruments other than mine, they actually let me pull them out so they weren't priceless. But I tapped all 7 violins I have in the basement, and all of them, except for the first 2 are tuned like that. The last 3 even more so because it is pretty much the Keith Hill area tap tuning method that I started using then. It seems that with the outline and arching they pretty much have to be like that don't they? I just make the area bigger and more even, the pitch is usually there already. I haven't figured out how to change the pitch. But I don't know how crummy my violins are, nobody's played them!

Ken

[Don Noon]

I haven't done that kind of tapping on old master instruments, but I have tried to see if tapping on various places with my 1gram spruce hammer would produce any sounds that corresponded to peaks in the impact spectrum taken from bridge taps. Other than finding some of the signature modes, it looked like a lost cause, so I gave up on that idea.

[Jeremyamoto]

After seeing a luthier in an Ida Haendal video do tap tests to her Strad, I've been trying this on many instruments with interesting results (Tapping the back, tapping the scroll with the strings dampened against your chest and lastly, blowing into the f-hole). Most instruments I've encountered have different tones for these three tests and very few had matching ones. The ones that did closely match felt much easier to play as overtones tended to really ring out.

Interestingly enough, of all the instruments I've played and tried throughout my shop travels, my Nemessanyi is one of the few to have all three match. In this case, it resonates at a solid C natural and the body resonates for about 5 seconds when you tap it. I wonder if the luthier who made the scroll for it had this in mind when he made it?

[lyndon]

Have you encountered any really good violins that did not have that type of tap tone?

Do you have any advice on how to 'hear' the tones? I'm not tone deaf, I can self tune my guitar and match notes perfectly but when I tap on my fiddle I can't hear notes. It just sounds like wood being tapped. Maybe I need to get a wood xylophone for comparison.

mike, i havent kept records or carefully studied every violins tap tones, as i never try to change the tones on old violins by slight regraduations, however my impression on good violins older than 1850, is if they dont have good tuning, theres usually some evidence of modification from original thicknesses, not just a new bass bar. i presently have what is probably one of my best for sale, a 1916 johannes brun swedish violin, that is not very well tuned, but sounds great

as to determining the tap tones, almost every violin is going to have its lowest tone on the bottom left and be a significantly higher tone on the bottom right and so on, the question is are these two distinct tones in tune (or not) with each other like from g-d on a piano or out of tune like between g-g# to c or some random out of tune sequence

to determine the tuning of one tap tone, use a piano or a keyboard possibly with a marimba sound, start with the centre of the bottom left of the top, play the notes on the keyboard around g below middle c and try to determine if the tap tone sounds higher or lower than the piano pitch. if the tap tones higher, for instance , try a higher note on the keyboard (if the tap sounds lower try a lower note on the keyboard etc)till you find the closest note on the keyboard to the tap tone on the violin. and so on to determine the other tap tone notes in the other areas

kenN i have considered what you are thinking, that this tap tone sequence is just a function of doing everything right, and thats how good violins come out, certainly the sequence of tones from lowest to highest; bottom left, bottom right, top left and right is true on almost every violin, but the relative tuning of the different tones will be completely random in my opinion if it is not tuned, as slight variation in one areas graduations can totally change that tap tones frequency and so on, without affecting the tuning of the other tap tones

for instance i would consider c-e,c-f,c-g (a third, a fourth, and a fifth)to be harmonic intervals, c-f#, or c-g# not so pleasant etc

[fiddlesurgeon]

When did the survey feature get added?

[donbar]

Lyndon, thank you for sharing your expertise on this matter and many other topics over the years.

I have also been tapping on violins for many years and agree with most of what you have just stated on this topic.

However one exception is that Keith Hill has indicated the lower right side of the top as the lowest or fundamental tap tone

with the smaller area outside of the bassbar on the lower left or bass side resonating a fifth higher in pitch.

I have found this relationship to be the true for evenly thicknessed top plates I assume because of the relative area of each side

with the bassbar as the dividing line. But I have also succeeded in reversing this relationship as you indicate by thinning the bassbar side of the top..

Have you ever found good violins with the lower bass side tap tone higher than the lower treble side tap tone ?

[Jacob]

for instance i would consider c-e,c-f,c-g (a third, a fourth, and a fifth)to be harmonic intervals, c-f#, or c-g# not so pleasant etc

What's your cut-off point for "harmonic intervals"? Unless you are into seriously unequal temperament, I would have thought that c-g# (=c- a-flat), a minor sixth, which is the inversion of a major third (like your c-e) would qualify as "harmonic"...??

[David Burgess]

I haven't done that kind of tapping on old master instruments, but I have tried to see if tapping on various places with my 1gram spruce hammer would produce any sounds that corresponded to peaks in the impact spectrum taken from bridge taps. Other than finding some of the signature modes, it looked like a lost cause, so I gave up on that idea.

Don, what are we gonna do? Maybe just let the folks most prone to hearing imagination have their day?

[lyndon]

donbar, from my understanding, a definetly from experience on clavichords, if left and right sides are equally thick, adding a bass bar will significantly lower the resonant frequency on the bass bar side, perhaps youre not tapping exactly where i am, although ive seen backs resonate higher on the bass bar side, on tops the bass bar side always seems lower, unless the grads are just totally weird, could keith hill possibly be talking about the back not the top or somehow got it back the front in print?

ps im not tapping over the bass bar, about an inch away, maybe from the bottom outside left about 1 1/2" in at a 45' angle, or directly above the middle of the chinrest

[lyndon]

Don, what are we gonna do? Maybe just let the folks most prone to hearing imagination have their day?

your one to talk, it seems it takes someone quite a bit of imagination to listen to one of your violins and think theyre hearing a stradivari, too, but you talk about it all the time.....

[Don Noon]

Don, what are we gonna do? Maybe just let the folks most prone to hearing imagination have their day?

I've said my thing, now going back to the shop. Caveat reador.

[David Burgess]

your one to talk, it seems it takes someone quite a bit of imagination to listen to one of your violins and think theyre hearing a stradivari, too, but you talk about it all the time.....

I eagerly await the evidence for this assertion.

Aside from that, naw, I can't hear your tap-tuning scheme, and also can't find technical support for what you think you might be hearing.

It's probably my own shortcoming.

[actonern]

Moderator?????????

How is this any different than "Zulu"????

[Janito]

How is this any different than "Zulu"????

You forget "Lama..."

http://www.maestronet.com/forum/index.php?showuser=24134

Some of us have memories.

[Addie]

Well, I have 3 Strads here on my bench. Tapping the side of the bridges...

Wait, this one says "Made in Czechoslovakia." You think I paid too much? Oh, and this one... never mind.

Oh well, back to the party.

[lyndon]

there was supposed to be a function that if you voted for category four, tune out anything i say, you didnt get to post

[stephen maloney]

with the strings dampened against your chest ...my Nemessanyi ...resonates at a solid C natural and the body resonates for about 5 seconds when you tap it...

TAP !

one one thousand, two one thousand, three one thousand, (still ringing) four one thousand, five one thousand.

?

[Bill Yacey]

with the strings dampened against your chest ...my Nemessanyi ...resonates at a solid C natural and the body resonates for about 5 seconds when you tap it...

Wow. That thing must set off seismographs when you actually put a bow to the strings!

[Craig Tucker]

there was supposed to be a function that if you voted for category four, tune out anything i say, you didnt get to post

Wow, thanks Lyndon, for providing a category I could choose!