# Pitch or frequency?

There seems to be confusion (certainly with me!) about the relationship between pitch and frequency. Trying to clear it up finds contrasting ideas. Obviously, when a note has a higher frequency than another, it is a 'higher' ( further to the right on a piano) note. Would it be correct to say the pitch of a note is, say, C, without specifying whether it's C4 or C5, for instance?

I'm not referencing the 'same note played on different instruments', but perhaps it's as simple as we call the frequency 440Hz as pitch 'A' (not always, I know), but there are other frequencies also called 'A' - like 220Hz, and 880Hz.

The other question is related (and my answer accepted), but that's all, I think.

• Commented Mar 31, 2018 at 14:30
• @user1803551, I don't think the linked question is asking the same thing as this question. The linked question seems to be based on a misconception of how pitches relate to frequencies. So while it might solicit answers with similar info, I don't think the question itself is the same (this question isn't based on a misconception, for example). I also think this one will be more useful to future readers with this same specific question. Commented Apr 12, 2018 at 20:21
• @jdjazz But my answer there answers the question here, and duplicates are considered by answer, and not by question. Commented Apr 15, 2018 at 8:40
• @user1803551 - surely a question would have a duplicate, rather than any answer to a question?
– Tim
Commented Apr 15, 2018 at 10:54
• You'd think so, but no, see here. Otherwise, I can just copy-paste my answer from there to here. Commented Apr 16, 2018 at 2:23

Frequency refers to the measurable number of cycles per second (Hz) of a periodic sound wave.

Pitch refers to (subjectively) how low or high that wave sounds to us as a note. The way I see it, pitch is the log-scale way that humans subjectively perceive frequency.

An unfortunate medical condition that highlights the difference between frequency and pitch is Diplacusis - people hearing the same frequency as different pitches in each ear.

Would it be correct to say the pitch of a note is, say, C, without specifying whether it's C4 or C5, for instance?

Out of context, it would be confusing, because C4 and C5 are not the same pitch - one sounds subjectively higher than the other. (It might be OK if it were obvious from context which C you were talking about).

In our musical system, I think it's OK in some contexts to say that C4 and C5 are the same note, as long as we're talking in a context where the idea of octave equivalence is understood.

• See also loudness (perception) versus intensity (measurable and scientific). Commented Mar 31, 2018 at 12:55

Would it be correct to say the pitch of a note is, say, C, without specifying whether it's C4 or C5, for instance?

It might be helpful to consider the distinction between a pitch and a pitch class. A pitch is a specific location on a keyboard: A4, for instance, is a pitch.

But a pitch class is a collection of all pitches related by octave equivalence. In other words, every single A on the keyboard (and every other A out there) belong to the pitch-class A.

Such a distinction is really helpful when understanding post-tonal music that operates on the notion of octave equivalency. Stravinsky's arrangement of Happy Birthday, for instance, is best understood from a standpoint of pitch classes.

I'd like to expand a bit the answers given by Нет войне and skinny peacock.

The terms pitch and frequency describe different things.

• Frequency is a physics property of a periodic signal,
• Pitch perception is a psycho-acoustics phenomenon.

In many musical situations the the fundamental frequency of a note and its pitch are very closely related, so it's common to associate these two terms. However, the perceived pitch is in fact affected by a list of factors, including harmonic content, inharmonicity, nonperiodic components and others.

Frequency of a periodic signal is well defined, and can be determined with tools like Fourier transform or autocorrelation. Pitch perception is subjective, and might not always be straight-forward to determine. It is a subject of scientific research, e.g. in topics like "what is the frequency of a harmonic sound that matches pitch of a sound including partials with some level of inharmonicity" and others.

A list of sonic illusions demonstrates various peculiarities of human hearing, e.g.:

Regarding octave equivalence, there are already some topics on Music SE:

I also encountered research in Tsimané community, suggesting that octave equivalence may not be universal to human, see e.g. https://www.quantamagazine.org/perceptions-of-musical-octaves-are-learned-not-wired-in-the-brain-20191030/

To combine it all in one simple answer - No, C4 and C5 are different pitches. They are the same 'pitch class', which might be loosely described in some circumstances as the same 'note'. But they are different pitches.

Frequency is the scientific description of pitch.

– Tim
Commented Apr 14, 2018 at 17:15

In my way of understanding, pitch in musical terms refers to the frequencies associated with musical notes, where as frequency might be associated with tones that are in between notes and not musical in nature at all. Pitch seems to be musical and frequency seems to be associated with Physics. Another way to look at it is pitches are things we can hear and frequencies can include pitches but can extend well below or above the capability of the human ear to perceive.

• We might refer to a note as being 'off pitch' if its frequency isn't quantised to the currently-established musical framework. But it would still have a 'pitch', albeli a wrong one! Commented Apr 14, 2018 at 17:25
• @skinnypeacock -- I do support your notion that frequency belongs to physics, but pitch belongs to perception. Any (audible) frequency can give rise to a pitch perception. Consider what we commonly call a "high-pitched sound." This does not need to lie in a particular scale to be meaningful. Or consider pitch-bending wheels on keyboards; it is still a pitch when it is bent.
– user39614
Commented Apr 15, 2018 at 15:52
• @skinnypeacock -- If you have a reference color, and try to match it but miss by a little bit, you might say that the second color is off. When a pitch doesn't quite match a reference pitch, the pitch is off, but it is still a pitch in the same way that the color that is off is still a color. Off-pitch doesn't mean "not a pitch", but something more like "not the reference pitch."
– user39614
Commented Apr 15, 2018 at 20:40
• @DavidBowling- This discussion is getting a little long winded but I've noticed one point that wasn't made clear before. Frequencies are measurable simply by counting the vibrations, no changes, where as pitches are seemingly not so absolute and may be varied slightly leaving a little wiggle room when applied to musical tones. Commented Apr 15, 2018 at 23:04
• @skinnypeacock -- Yes, it is a bit long-winded, sure to be banished to chat at any moment. Your last comment hits on the point I was trying to make from the start: frequency is an objective, measurable quantity, while pitch is a subjective perceptual phenomenon. Pitch is how we interpret sound wave frequencies.
– user39614
Commented Apr 15, 2018 at 23:14

...relationship between pitch and frequency...the pitch of a note is, say, C, without specifying whether it's C4 or C5, for instance?

• frequency: how often something regularly repeats, standard unit of measure is hertz.
• pitch: the frequency of sound vibrations which is also subject to a number of psychological perception aspects.
• pitch class: a pitch and all of its octaves, designated by letters A-G with special treatment of B, and additional H, in German music theory.

Pitch is how high or low a note sounds (pitch is determined by vibrations in a sound wave, the quicker the vibration, the higher the sound).

The measurement of pitch is done with the `Hertz` unit (or `Hz`).

`Hertz` is a measure of frequency which indicates the number of oscillations in a second.

So to answer your question: YES, pitch is the same as frequency. Which one you use depends on the context, if your talking to an engineer or tweaking an equalizer then you would think in terms of frequency but if numbers don't matter where, for example, you are talking to a singer or song writer then you might use pitch to indicate higher or lower tones.

You could use pitch to indicate `C` if you were talking about a specific `C` but didn't explicitly state the octave. In which case you're talking about `C4` for example but you left out the `4`. `C` on its own is still a reference to pitch but if you were talking about any `C` then pitch class is a more appropriate term to use.