When I press C2 on my piano, I hear E4 and G4. When I press B3, D4, F4 and A♭4, I hear G2. I don't know why this is. It's like the soundwaves lead somehow to the major-quintachord C-E-G and to the little-dominant nonachord G-B-D-F-A♭. How is this possible? I'm not pressing E4 or G4 or G2, but they make the sound.

Why do I hear this? How is this possible? I have the perfect pitch so it's possible that I maybe hear what others don't, but how can I hear full chords from pressing a few keys?

  • 2
    Are you holding the sustain pedal when these sounds happen?
    – Bob
    Commented Feb 5, 2017 at 22:15
  • What model of piano? Commented Feb 5, 2017 at 22:31
  • 3
    Sympathetic resonance?
    – endorph
    Commented Feb 5, 2017 at 22:36
  • 1
    Much of this could be explained simply as harmonics / missing fundamental. All tonal tunings approximate harmonic ratios within their intervals. However, already the major thirds are substantially off in 12-edo pianos. The minor seventh (F4 from G1) approximates the harmonic seventh, though only if we're very generous_. What really doesn't fit in though is that A♭. Commented Feb 5, 2017 at 22:52
  • 5
    Open the piano top, and feel if any strings apart from the pressed keys are vibrating. Only the top octave or two should, as they're not damped.
    – Tim
    Commented Feb 6, 2017 at 8:53

1 Answer 1


Whenever you play any note on the piano (or anything else), the sound contains not only the pitch you played but the overtones of that pitch. The E and the G are both overtones of the pitch C, so those strings are vibrating in sympathy with those overtones from the C. That's why you hear them too. (If the other strings were perfectly damped you wouldn't hear this. Either the damper pedal is depressed, or the damper felts aren't working properly. If the overtone sounds bother you, get the dampers fixed!) I think it's cool that you heard these overtones and noticed them. A lot of people hear it but ignore it. Too bad!

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.