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When I try to copy a tune or watch other people play the piano, I sometimes hear a note that isn't there. Especially top note is the case. My teacher said that it is related to harmonics, told me that if you smash down a c note, there are lots of sounds you can hear otherwise of just a c note. Then, my question is,

1) Is this occasional phenomenon normal and do you sometimes have the same problem as I do? 2) If you have absolute pitch, does this bother you?

  • Do you always hear notes not notated on the score? I basically only hear such notes if many instruments are playing the same note (probably in different octaves) at the same time, and the additional unnotated note is destroyed if a different notated note is added into the mix. – Dekkadeci Aug 26 '19 at 23:53
  • No, not always. I usually listens to Jazz music so I assume that there might be some difficulty knowing what voicings and chords were used, hence the magic tricks like I mentioned on my question, perhaps? – Victoria Aug 26 '19 at 23:57
  • What kind of notes are you hearing? If I played, say, a root position D7 chord, what note would you hear above it? D? F♯? Something else? Is this only on a certain piano? Is this also present in recorded music, or just live? Does it seem to matter how high or low the real notes are? As much info as you can give us would help immensely, if you please. Does loudness matter? Etc. – user45266 Aug 27 '19 at 0:46
  • I forgot to mention that I hear those notes 'sometimes'. It doesn't bother me much since my ears are not trained to be a musician. But the occasional phenomenon I questioned in this website felt real fun and to be discussed with. – Victoria Aug 27 '19 at 0:57
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Its not a problem at all. These are called overtones and are produced with each note without actually being played. You may happen to have a better ear for them than most, but every single note you hear consists of many pitches. (The only exception is a sine wave, which is a pure tone with no harmonics. A tuning fork comes close, but still has them.) The harmonic series tells us, mathematically, what notes will sound good together and what notes will clash. It explains why a major chord sounds different than a minor chord, and many other aspects of music and harmony that we often take for granted. Each instrument, based on size, shape, material, etc emphasizes different harmonics, giving it a distinct sound, even between different models of the same instrument. (There are, of course, many other factors involved in creating a specific sound.)

The note you play is the fundamental. The most prominent harmonic is almost always one octave above the fundamental, vibrating at a ratio of 2:1, and can be quite hard to discern as every other oscillation aligns with the fundamental.

The next harmonic is often the easiest to hear as it is farther away from the fundamental, but still prominent and low enough. It vibrates at a ratio of 3:1 with the fundamental, which puts you an octave plus a fifth above. If C is our fundamental, this would be G.

We continue up the series with the ratios 4:1 (a fourth above the previous harmonic, 2 octaves above the fundamental), 5:1 (up another major third), 6:1 (up another minor third, now 2 octaves above the second harmonic), and so on (7:1, 8:1, 9:1), until they are too high for us to hear.

Notice how the most consonant intervals (octave, fifth, fourth, major third, minor third...) are closest to the fundamental. More dissonant harmonies occur further up, and are mostly imperceptible. (What actually determines how consonant two notes are is the number of pitches that overlap in their respective harmonic series. The less they overlap, the more dissonant the interval.)

Tuning based on the harmonic series is called Just Intonation and is the only way to be perfectly in tune, but the ratios create notes that are unique for each key. To avoid tuning to a new fundamental every time we change keys we created the Equal Temperament tuning system, which closely approximates pitches from the harmonic series, while keeping the distance of each half step constant (but also preventing you from ever truly being in tune!)

The human voice is incredibly good at creating overtones, since we can dynamically change the shape of virtually all parts of the "instrument" on the fly and can produce any microtone, allowing us (with lots and lots of practice) to accurately tune to the harmonic series of whatever the fundamental happens to be at the moment.

Just for fun, try singing the word "we" on a relatively low, but comfortable pitch (doesn't have to be in tune with anything). Now do it again, but REALLY slowly, shifting from the "oo" sound at the beginning to the "ee" sound at the end as gradually as you possibly can (also try to create a lot space in the back of your mouth). If done right, you should hear at least part of the harmonic series in ascending order.

  • Also, fun fact, the reason why tighter harmonies sound more muddled the lower they are (and you rarely find anything closer than a fourth below an A2) is because more notes in their harmonic series are within our hearing range meaning there are more audible notes to misalign, creating dissonance. – WillRoss1 Aug 27 '19 at 2:40
  • 'The harmonic series explains how a maj. chord sounds different from a min. one.' How? And do we/can we 'tune to the harmonic series'? Why would we want to do that? If it works, it'll only be the first couple of harmonics anyway, much the same as in a lot of instruments (the later harmonics go quiet quickly). – Tim Aug 27 '19 at 12:39
  • @Tim The identity of any chord is the sum of the wavelengths of each pitch in the harmonic series of each note in the chord. The fundamental pitches in a major chord have a ratio of 4:5:6, with the 3rd 2 octaves below the 5th harmonic of the root and the 5th an octave below the 3rd harmonic of the root. This high level of overlap between the most prominent pitches in the harmonic series creates a relatively simple wavelength with a repeat period of only 4 cycles. – WillRoss1 Aug 27 '19 at 15:31
  • The minor chord has a more complex ratio of 10:12:15. It, of course, has the same relationship with the 5th, but now the 5th is 2 octaves below the 5th harmonic of the 3rd, which is slightly weaker than the root to 3rd ratio found in the major chord. The minor chord has a repeat period of 10, giving it a similar, but distinct sound from the major chord (compared to the 160 repeat period of a diminished). Indeed, these ratios define the unique sound of each chord structure (regardless of the root), major and minor were just the most obvious examples. – WillRoss1 Aug 27 '19 at 15:31
  • As for tuning to the harmonic series, it is true that many of the ratios cannot be heard audibly as they are too high or too quiet, but they are still there mathematically. Eventually the ratios become so close together that literally any note will, at some point, fall within the harmonic series. When tuning with Just Intonation we use the lowest partial that meets our needs. – WillRoss1 Aug 27 '19 at 15:34
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[Partial answer]

Hmmm, harmonics would be my best guess. As you know, harmonics (or overtones, or partials) are present in every note played by a piano; it's possible that you're hearing some of these notes (they're definitely possible to hear and mentally isolate, even under normal circumstances). Not sure why you would be especially sensitive to this, though.

Another possibility: Is this only a problem with only one certain piano? If so, it might be the case that one note is sort of "stuck" in the depressed position, and when some other note is played, the note is sympathetically resonating (I would think that your teacher would be able to hear that, though)...

It is also possible that you have tinnitis, and are hearing a ringing note in your ear, but I think that's highly unlikely unless I'm missing something hear. That would, however, fit the "annoying people with absolute pitch" bill...

I hate to mention this, but I don't really know you, so is it possible you're misidentifying something? Is it possible you're mislabelling a note or somehow hearing notes that aren't there?

Sometimes, when multiple notes are played at once, certain other notes can be perceived. Look up "ghost soprano" here on this site, or try researching barbershop music's resonant chords. It could also be sum-and-difference tones of some sort, so this could be an acoustic phenomenon.


I asked one of my friends who has absolute pitch about whether this would bother them. They said it would bother them if the note were anything but a multiple of an octave above/below the actual notes, since that would mess with pitch recognition, but with so little info, beyond that my friend wasn't really sure. Neither my friend nor I nor anyone I know has had this issue before, so I look forward to seeing other hypotheses, and eventually the correct answer.

  • Huh, I generally find it cute instead of annoying whenever I hear a ghost note (and it's inevitably not the same pitch class as the actual notes--e.g. given that all I play are C's, the ghost note is a G), and I have absolute pitch. – Dekkadeci Aug 27 '19 at 6:58
  • There is a phenomenon about two notes played together makes a third note sound. Can't find it yet... – Tim Aug 27 '19 at 12:42
  • @Dekkadeci I think my friend meant more like if they were hearing the higher "ghost note" and were unable to recognise the actual note, but I'm just guessing. I probably should have asked for clarification on that... "Cute", huh? I would have guessed more along the lines of "cool", but I guess that's why I'm asking :P – user45266 Aug 27 '19 at 14:54
  • @Tim The first thing that comes to mind for me for that is either sum-and-difference tones or Tartini tones (two terms for the same thing, I think...?), on string instruments, erhaps? – user45266 Aug 27 '19 at 14:55

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