5 ms·

Can you clarify harmonic vs overtone?

by hashkb 6y ago

SeanLuke 6y ago
All sound waves can be defined as the sum of a (possibly infinite) set of different sine waves. Each such sine wave naturally has a frequency (a pitch), an amplitude, and a phase. If you break a wave into its constituent sine waves like this, each sine wave is known as a PARTIAL. Sound waves that we perceive as tonal -- as musical -- commonly consist with partials which follow a certain pattern. Namely, there is one lowest partial, and most or all of the higher partials have frequencies which are INTEGER MULTIPLES of the this lowest partial's frequency. For example, if the fundamental is at 200Hz, perhaps the next lowest partial is at 400Hz, and the next one might be at 600 or 800Hz, and so on. When partials are organized like this, they are known as HARMONICS. The lowest such partial -- the lowest harmonic -- is called the FUNDAMENTAL, and the remaining (higher) harmonics are known as the OVERTONES. It is common, but not always the case, that the fundamental (1) defines the pitch of the sound (2) is the loudest harmonic. Overtones instead tend to add color to a sound.
- hashkb 6y ago
  So all overtones are harmonics. All harmonics except the fundamental are overtones? Edit: I never realized the fundamental was a harmonic. I thought all harmonics had to be above the fundamental. I thought the overtones were the multiples (e.g. higher octaves) and harmonics were other intervals produced by the instrument (organs being the most extreme example and maybe oboe being the least)
  - schoen 6y ago
    Might be a terminological ambiguity -- like in mathematics you can distinguish "subsets", "proper subsets", and "nontrivial" (or "nonempty") subsets. Or "divisors" and "nontrivial divisors" and "proper divisors". Even though the terminology can be defined in order to make these distinctions clear, there's an arbitrariness in terms of which definition you prefer (in the past, some mathematicians treated 1 as prime, which makes the definition of a prime simpler, but makes many theorems about primes more complicated to express). And there's a likelihood that even experts will sometimes use the simple term informally when they technically mean a more specific thing (like occasionally saying "divisors" instead of "proper divisors", or something). I imagine that acoustics experts have a definition available that definitively states whether the fundamental "is" a harmonic, but in certain contexts it intuitively makes sense either to include or exclude it, regardless of that. A similar case might be "animals"; taxonomically humans are animals (and apes), which is very important sometimes and confusing other times.
    - hashkb 6y ago
      The fundamental being in or out of the set is less interesting to me than the (useful, to me in my day to day) distinction between overtones and harmonics. Technical misunderstandings really mess up rehearsals so I try to be as accurate as possible with the objective stuff so I can use it to communicate the subjective stuff.
  - enriquto 6y ago
    > So all overtones are harmonics. Not at all! It's the other way round. Harmonics are those overtones that are integer multiples of the fundamental. You can have other, non-harmonic, overtones.
    - hashkb 6y ago
      Just to make sure I've got it: harmonics will always sound like (be?) octaves relative to the fundamental. But all the less-dominant frequencies are overtones, even if I somehow get a tritone or something gross sounding. Now what happens when I play a chord and get overtones out of the interaction between two strings or a choir? What's happening there?
      - enriquto 6y ago
        > Now what happens when I play a chord and get overtones out of the interaction between two strings or a choir? What's happening there? Nothing. Sound superposition is linear. There's no interference between different frequencies. By playing several strings together you obtain the sum of the sounds played by each of them separately. No new frequencies can appear.
        ghusbands 6y ago
        Overly simplistic. You can get beats when you combined two nearby frequencies. The beats have a frequency and are audible. Similarly, sounds can be reinforced or hidden in the interaction between instruments; it might be linear, but that does not say anything about what you actually hear.
        tripa 6y ago
        Overly confrontational. You can and do get beats when combining nearby frequencies, and it's not at odds with sound superposition being linear. The beats have a frequency and are audible, but their frequency is not a pitch.
      - djeiasbsbo 6y ago
  - SeanLuke 6y ago
    The fundamental is harmonic #1. This is the case for essentially all additive synthesizers for example. Overtones are any partials other than the fundamental. While overtones CAN be non-harmonic (notably in bells), I think it's fair to say that most of them, or at least the most important ones, are usually harmonics. This is because the terms "fundamental" and "overtone" are historically music terms, and are generally applied to sounds we perceive as tonal or musical: and such sounds are largely composed of harmonics.

Can you clarify harmonic vs overtone?

by hashkb 6y ago

Can you clarify harmonic vs overtone?

All sound waves can be defined as the sum of a (possibly infinite) set of different sine waves. Each such sine wave naturally has a frequency (a pitch), an amplitude, and a phase. If you break a wave into its constituent sine waves like this, each sine wave is known as a PARTIAL. Sound waves that we perceive as tonal -- as musical -- commonly consist with partials which follow a certain pattern. Namely, there is one lowest partial, and most or all of the higher partials have frequencies which are INTEGER MULTIPLES of the this lowest partial's frequency. For example, if the fundamental is at 200Hz, perhaps the next lowest partial is at 400Hz, and the next one might be at 600 or 800Hz, and so on. When partials are organized like this, they are known as HARMONICS. The lowest such partial -- the lowest harmonic -- is called the FUNDAMENTAL, and the remaining (higher) harmonics are known as the OVERTONES. It is common, but not always the case, that the fundamental (1) defines the pitch of the sound (2) is the loudest harmonic. Overtones instead tend to add color to a sound.

hashkb 6y ago
So all overtones are harmonics. All harmonics except the fundamental are overtones? Edit: I never realized the fundamental was a harmonic. I thought all harmonics had to be above the fundamental. I thought the overtones were the multiples (e.g. higher octaves) and harmonics were other intervals produced by the instrument (organs being the most extreme example and maybe oboe being the least)
- schoen 6y ago
  Might be a terminological ambiguity -- like in mathematics you can distinguish "subsets", "proper subsets", and "nontrivial" (or "nonempty") subsets. Or "divisors" and "nontrivial divisors" and "proper divisors". Even though the terminology can be defined in order to make these distinctions clear, there's an arbitrariness in terms of which definition you prefer (in the past, some mathematicians treated 1 as prime, which makes the definition of a prime simpler, but makes many theorems about primes more complicated to express). And there's a likelihood that even experts will sometimes use the simple term informally when they technically mean a more specific thing (like occasionally saying "divisors" instead of "proper divisors", or something). I imagine that acoustics experts have a definition available that definitively states whether the fundamental "is" a harmonic, but in certain contexts it intuitively makes sense either to include or exclude it, regardless of that. A similar case might be "animals"; taxonomically humans are animals (and apes), which is very important sometimes and confusing other times.
  - hashkb 6y ago
    The fundamental being in or out of the set is less interesting to me than the (useful, to me in my day to day) distinction between overtones and harmonics. Technical misunderstandings really mess up rehearsals so I try to be as accurate as possible with the objective stuff so I can use it to communicate the subjective stuff.
- enriquto 6y ago
  > So all overtones are harmonics. Not at all! It's the other way round. Harmonics are those overtones that are integer multiples of the fundamental. You can have other, non-harmonic, overtones.
  - hashkb 6y ago
    Just to make sure I've got it: harmonics will always sound like (be?) octaves relative to the fundamental. But all the less-dominant frequencies are overtones, even if I somehow get a tritone or something gross sounding. Now what happens when I play a chord and get overtones out of the interaction between two strings or a choir? What's happening there?
    - enriquto 6y ago
      > Now what happens when I play a chord and get overtones out of the interaction between two strings or a choir? What's happening there? Nothing. Sound superposition is linear. There's no interference between different frequencies. By playing several strings together you obtain the sum of the sounds played by each of them separately. No new frequencies can appear.
      - ghusbands 6y ago
        Overly simplistic. You can get beats when you combined two nearby frequencies. The beats have a frequency and are audible. Similarly, sounds can be reinforced or hidden in the interaction between instruments; it might be linear, but that does not say anything about what you actually hear.
        tripa 6y ago
        Overly confrontational. You can and do get beats when combining nearby frequencies, and it's not at odds with sound superposition being linear. The beats have a frequency and are audible, but their frequency is not a pitch.
    - djeiasbsbo 6y ago
- SeanLuke 6y ago
  The fundamental is harmonic #1. This is the case for essentially all additive synthesizers for example. Overtones are any partials other than the fundamental. While overtones CAN be non-harmonic (notably in bells), I think it's fair to say that most of them, or at least the most important ones, are usually harmonics. This is because the terms "fundamental" and "overtone" are historically music terms, and are generally applied to sounds we perceive as tonal or musical: and such sounds are largely composed of harmonics.