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Talking here with my nephew - he wants to know why certain recorded sounds sound different from one another. For example, a violin playing a single note sounds different than a guitar playing the same note. Why? Aren't they playing the same "frequency"? or is it more of an array of frequencies playing the same note?
Follow Ups:
Where to begin: Shape and size of the instrument body means that they resonate at different frequencies and intensities, the string length, tension, and likely construction of the strings, the bridge is very different as well. Violin bodies are much stronger resonators than a guitar body. This is why they are generally a much louder instrument than a guitar (the orchestra would have to play very quietly for an acoustic guitar concerto to not drown out the poor fellow).Forget what guys are saying below about plucking vs. bowing, this is silly because you can just as easily pluck a violin string as bow it (its called pizzicato) and I can tell you from living for 4 years with a violinist that a plucked violin, viola or cello sound nothing like a guitar or each other for that matter.
The complex harmonics and overtones produced by the shape and composition of the instruments (wood body, bridge, string etc.) are simply different and different guitars will sound different from one another as well for the same (albeit more subtle) reasons.
A guitar is generally plucked. A violin is generally bowed, although sometimes plucked. Since this difference is obvious, I will assume that you are referring to the difference in the overall sound quality of the instruments.The answer is that each instrument produces different levels of various overtones along with the fundamental tone. This is referred to as the "acoustic spectrum" or "timbre" of the instrument, and can be seen in graphical form as a spectrogram.
Using the violin as an example, if we set a reference level as the level of the fundamental tone of a note (let's take A-440), the level of the second harmonic (first overtone) may be approximately 10 to 12 dB lower, and the third harmonic may be approximately 15 dB lower.
Contrast this to an acoustic guitar, where the second harmonic may be several dB LOUDER than the fundamental, and the third harmonic may be approximately equal in level.
Obviously, these relative levels vary from one model to another, which is why not all violins sound the same.
In other words, each instrument produces overtones at many frequencies, and it is the relative level of each overtone which produces the instrument's characteristic "timbre", or sound quality.
Now that you've received many responses to your question, it is up to you to decide which 2 or 3 of them actually contain pieces of useful and accurate information, and which ones are "full of it". But since you asked the question, you're really not in a position to "grade the papers", are you? Which is why I suggest you find a good authoritative book on the acoustics of musical instruments. A good starting point is Harry Olson's "Music, Physics and Engineering", available from Amazon.com.
listen to Mahavishnu Orchestra's "Miles Ahead" from their album Birds of Fire. He plucks a violin and trys to make it sound guitar-like. Of course the biggest reason is it's not a guitar. The string is shorter the body is smaller and so on and so on. Also picked vs plucked is different even on the same instrument.
That is, the 'attack' or 'starting transient' is different.All humans detect what instrument it is, by paying most attention to the attack, which 'fully characterises' the instrument, resonances, harmonics, and all. And then, we pay more attention to the decay, than to the sustained component of a note also known as the 'continuous tone'.
With a guitar, because it is a member of the instrumental group where there can be little or no sustain per note, the decay plays the next biggest role in our identification.
[For identifying an instrument, which CAN do sustain, the continuous tone is STILL the least important part of any note to our hearing and to our affective responses. Also, that most expression is in the attack and the decay, much more so than the production of continuous tone.
Given that many instruments, like pianos and percussion just don't have a continuous or sustain component in any notes, this ought to make sense. {:-| !
Because all instruments, even different makes of the same instrument, STILL have distinguishing timbre, don't they!?
As do musicians! Again, it is mostly in how they start and finish notes!
So, what is called 'the characteristic timbre' of an instrument is identified using the attack and decay. The sustain or continuous tone (with such an instrument's harmonics) is, relatively, unimportant to our hearing and affective systems. ]
This reply is a complete and sufficient answer to your query. Apart from Clark none of the others got more than close. And, Clark WAS more succinct than I!
WarmestTimbo in Oz
The Skyptical Mensurer and Audio ScroungerAnd gladly would he learn and gladly teach - Chaucer. ;-)!
'Still not saluting.'
a French horn and a trombone playing the same pitch. Same attack, same decay, same sustain. I'm afraid your definition of timbre cannot be stretched quite this far.Timbre is in the sustain. Anybody can tell a bowed violin from a plucked guitar. But the attacks and the decay characteristics tell us nothing about the timbre. And *that's* where the relative strengths of the harmonics enter the picture.
"So, what is called 'the characteristic timbre' of an instrument is identified using the attack and decay."Well if attack and decay include everything including the kitchen sink, then it's pretty hard to parse out any meaningful subset from there. I mean, if that's the way it's defined, then just say "timbre" as a catch-all term and say that's the way it sounds, just because it does. There's only a couple of meaningful parts to timbre, attack and decay, and it includes all? Interesting definition, and not a real good one for engineers.
Engineers like to separate these things into more components to analyze. An attack and decay ENVELOPE is something different, and only talks about the amplitude modulation change with time. There's frequency spectrum in there as well, but that is a subcomponent.
But hey, if you just want to call the attack and decay an all inclusive time domain representation of the rise and fall in amplitude of the note, then of course you can recognize an instrument in this interval. It, after all, includes all the information you say it does. To me it's a rather weak term, to lump sum everything in that interval. It has no interesting features to talk about, it is too inclusive to talk about the various component features. But okay, if that's the true musical terminology, then I learned something.
Then let's just say a guitar and violin sound different based on their timbre, which is to say the total sum of everything that makes up their sound. Wow, what a concept! Obviously, this is true, it is the definition of the differences in the way they sound!
The only point you have elsewhere is that the timbre of the instrument is most recognizable by the attack and decay portion of the timbre of the instrument. That too is obvious, and not all that interesting, to be honest.
I may have been wrong to assume attack and decay as the amplitude modulation envelope of the instrument's sound, but if it does include the harmonic spectrum and all else, then there's really not much to discuss at all.
If the sound is most important in just the attack portion, again, it too is so inclusive as to be not significant an analysis of what is really important. It just says it's all important, at the beginning, and that's enough. Well, duh! We could all could have figured that out.
So I guess I don't really see the point of the argument with these definitions.
.
nt
Best Regards,
Chris redmond.
Short answer: as others have written, different instruments are different sizes, shapes, methods of playing, etc. Or to compare vocalists, Robert Plant and Bob Dylan, different shapes of vocal cords, different lung capacities, different builds of the chest's resonant cavity, etc.Longer answer: Pitch is an abstraction generated by the brain. A sound wave in most cases is not a pure pitch (unless you are listening to a signal generator). The brain is able to hear many types of sound and pick out a pitch like C or F.
This is like the many shades of red. You can look at a hundred colors and they will all be red, but no two will be the same. That is also an abstraction of the brain. And it is cultural as well.
What is the same in the many sound waves that are heard as a C note is that they all have the same fundamental frequency. Beyond that, they can be very different and still be heard as a C. Harmonics, attack, decay, sustain...just because a sound is a C does not mean much as to how it is going to sound. You need much more information.
Yes - I was looking for your longer answer - but makes me wonder if all tone generators sound the same - or should sound the same, theoretically.
It's extremely hard to hear pure tones as sounding different through different amps into the same speakers. This might be the case where all amps do sound the same. Unfortunately when it gets more complicated, the differences start to appear. And I don't understand why two theoretically clean amps will part ways and start sounding different when they measure so close, but it does to me and many others. Yet when I try a sinewave, it always just sounds like the same sinewave.
A pure tone generator is a sine wave. In theory, these should all sound the same...but our world is not theoretical.The pure sine wave may have some distortion added from the electronics. Or, even more likely, whatever speakers that are used may add a signature of their own. This would mean that you are not hearing a pure sine wave anymore...so it would not sound the same through different speakers, possibly.
If any 2 signal generators are putting out a pure sine wave (within negligible real world errors) into the same electronics and speakers, same volume level, I would expect them to sound exactly the same.
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or don't you have a personal opinion on this subject?
Because the two instruments have different harmonic structures. Different timbre. Different sizes, different shapes/sizes of the sound hole, etc. Even two violin's or two guitars will sound somewhat different from one another. Which is why I insist on my audio system maintaining the harmonic structure of the musical waveform. Most speakers destroy it.
You audiophile hysterics.
- This signature is two channel only -
End of story.
The answer to everything is in the good book.
...I think she uses ultra-refined low-power SETs.
And they went extinct. Presumably because god wanted it that way.
- This signature is two channel only -
What more could one ask?...
nt
as the other's have said, very few notes on any instrument consistent of any one frequency. There is the frequency of the primary note, but on most good violins, the second harmonic is actually louder than the primary if you look at the plot of a spectrogram. A good violin could have at least a dozen separate tones in a note. On my violin, certain notes totally drive an electronic tuner bonkers. Also, regarding violin and guitar, the sound production and amplification is completely different- an acoustic guitar has the string vibrating over the soundhole, and the body is basically a big box that gives it resonance and some reflection. A violin string vibrates the bridge, which vibrates the top plate and the soundpost, and the plates actually vibrate and move the air, not the string. People who get hung up on the frequency thing end up w/ bad stereos and not understanding music, so broaden your son's horizons.
Overtones on the continuous tone / sustain, can't be the full story. If only because some notes and some instruments don't HAVE sustain, like guitars and their notes.So, how notes are begun and stopped/decayed MUST be where it's really AT. Eh?!
As a chorister for many years, trained under the RSCM's rules, we used to say 'if yer can't pitch, yer can't pitch'.
Attacks and decays are where it's all at.
WarmestTimbo in Oz
The Skyptical Mensurer and Audio ScroungerAnd gladly would he learn and gladly teach - Chaucer. ;-)!
'Still not saluting.'
the violin can be played pizzicato, the guitar can be bowed, a la Jimmy Page, and the various attacks and decays can be duplicated on both instruments. I play both- and can do that easily. But even with the exact same decay and attack, the tones are very different. Attack and decay to play a large part in defining any tone and are very important, but not to explain the diff the original poster asked. There's tons of physics on the web about this- and one of the best research groups is in Oz, so check it out.Here's a link to get you started- visit other links in this group. All fascinating.
Get hold of a cheap electronic keyboard - Casio, fer instance - and you can show your nephew, rather than talking to him about it.Any instrument playing "middle C" (that's about 420Hz, isn't it?) will sound different to a 420Hz sine wave. That's because the instrument produces a heap of overtones (multiples), as well as the basic frequency ... and different instruments (or even using strings made of different materials in the same instrument) produce different harmonic combinations.
A typical electronic keyboard will have different buttons to press for 'piano' tone, 'organ' tone, 'harp' tone ... etc. All these are doing is selecting different harmonic patterns on top of the base frequency but the result is easy to hear.
Regards,
And I certainly don't mean to be rude or sound like a know-it-all. I'm hardly a know-it-all as I am all to aware that I know not much at all.
The majority of the frequencies might be middle C, but it's accompanied by a bunch of other tones that make up the sound of the instrument.
You said: "The majority of the frequencies might be middle C, but it's accompanied ...".Actually it's "The base frequency is middle C, but it's accompanied ...".
Regards,
Each instrument has a "timbre", the way it sounds. Timbre is the sum of the attack, decay, harmonics, and extraneous noise that an instrument plays.A bowed instrument has a different attack and decay than a plucked instrument, for example. And each stringed instrument has a different set of harmonics, or multiples of the note played, that each note has, plus the "Shzzit" factor, as Itzhak Perlman called it. The "shzzit" off a violin is nothing profane, it's just the extraneous noise not related to the note or harmonic of the note that usually is caused by rosin shrieking or something of that sort. Close miking shows off more shzzit than far miking, where far miking shows more body vibration sound than string and rosin sound.
Every instrument has fundamental and harmonic sound, attack and decay, and some other extraneous noise unrelated. Sometimes it's the hammer of a piano strike or the clicking of valves of the flick of a fingernail on a string of a guitar. All of this comes into play.
And to add - The result is a combination of the excitation frequencies - A bow excites less of a range than a "pluck" as the excite the mechanical and acoustical resonance amplitudes and damping values of the instrument - then how the various noise sources of the instrument - strings, face, neck, back, etc. interfere with each other as the sound reaches the ear or the microphone.
Very different instruments. A violin has a very small body, a short neck, and a short string length. A guitar has a large resonant body, a longer neck, and thus a longer string length. The longer the string, the more it vibrates when plucked.
or why does Robert Plant sound different from Rod Stewart if they both sing the same note?
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