What Is Concert Pitch? A Pitch Changer Guide

Concert pitch is the tuning reference that musicians, instrument makers, and any Pitch Changer assume: the A above middle C (A4) sounds at 440 Hz. That's why people call it A440, or write A=440 Hz. Every other note in standard tuning is worked out from that one frequency.

Most music you'll come across sits on or near A440, but plenty doesn't. Some orchestras tune a little higher. Some recordings drifted because of tape speed. A few artists tune to 432 Hz on purpose. Knowing how far off a track is, measured in cents, tells you whether it matters and which tool can fix it.

What concert pitch means

A tuning reference is a single agreed note. Once A4 is fixed at 440 Hz, the rest of the scale follows from equal temperament, where each semitone multiplies the frequency by about 1.0595. A5 is 880 Hz, A3 is 220 Hz, and middle C comes out at about 261.63 Hz.

The reference is what lets a piano, a guitar, and a sample library play together without clashing. If everyone agrees on A, everyone agrees on every other note too.

A short history of A440

Pitch wasn't always standardised. For centuries the frequency of "A" varied by city, by period, and by instrument. Baroque ensembles today often play at A=415 Hz, roughly a semitone below modern pitch, as a nod to the lower tunings that were common back then.

An international conference held in London in 1939 recommended A=440 Hz as the standard. ISO first published it as a recommendation in 1955, and in 1975 it became the standard ISO 16. That's the standard most tuners, DAWs, and audio software still default to.

Why some orchestras tune to 442 or 443 Hz

A440 is the reference, but not every ensemble sticks to it. Many European orchestras tune slightly higher, often to 442 or 443 Hz. The usual reason given is that a higher A sounds a touch brighter, which is a matter of taste rather than measurement.

The gap is small. Cents measure it:

cents = 1200 × log2(f ÷ 440)

• 442 Hz is about +7.85 cents above A440
• 443 Hz is about +11.8 cents
• 415 Hz is about −101 cents, so close to one full semitone down

Eight cents is near the edge of what many listeners notice when two tones are played one after the other. If cents are new to you, Semitones and Cents: A Pitch Changer Guide explains the unit.

What about 432 Hz?

A=432 Hz has a vocal following online. Some people claim it's more "natural" or has calming or healing effects. There isn't good scientific evidence for those claims, and a handful of small studies don't change that. It's simply a different reference pitch.

How different? 1200 × log2(432 ÷ 440) comes to about −31.8 cents, roughly a third of a semitone flat. That's enough to hear when you play a 432 Hz track next to an A440 instrument. The two will sound out of tune with each other, even though each is in tune on its own terms.

Old recordings and tracks that sit between keys

Not every off-pitch track was tuned that way on purpose. Tape machines didn't always run at exactly the right speed, and records were sometimes mastered or transferred a little fast or slow. Even a small speed change moves the pitch. How Pitch, Speed, and Duration Relate shows why the two are linked.

The result is a song that sits somewhere between two keys: say, 20 or 40 cents sharp of A440. Played alone, it sounds fine. Played against a keyboard, a backing track, or another song, it clashes.

Why this confuses a key finder

Vocal Cut's Key Finder builds a profile of which notes appear most in a track. To do that, it maps every frequency to the nearest semitone, assuming A = 440 Hz. It doesn't try to measure or correct for a tuning offset.

A track at 442 Hz is only about 8 cents off, so every note still lands on the right semitone and the result is unaffected. A track around 50 cents off, a quarter-tone, is a different story. Notes fall right between two semitones and get split across both. The profile smears, and you can get the wrong key or a low-confidence result. A 432 Hz track, at about 32 cents flat, is less extreme but can still blur things on some material. Wrong Key Detected? Fix Your Key Finder Results covers this and other common causes. For the basics of what a key is, see What Is Musical Key? A Key Finder Guide.

Matching samples to your project

Tuning offsets show up most in sampling. Drop a loop from an older record into a project built at A440 and it can sound sour against your chords, even when it's in the right key. The notes are right, but the tuning is off by some number of cents.

The fix is a fine-tune control in your DAW or sampler, which shifts the sample by cents until it lines up. Do it by ear against a sustained note, or check with a tuner. For pulling the sample out in the first place, see How to Cut a Sample or Loop From a Song and How to Sample Vocals Cleanly.

What an online pitch changer can and can't fix

Vocal Cut's Pitch Changer is a music pitch changer that moves audio in whole semitones from −12 to +12. You can load an MP3 or any other format your browser decodes. It has no cents or fine-tune control.

That's the honest limit. It can't retune a 432 Hz recording to 440, because that's a 32-cent move and the smallest step is 100 cents. The same goes for nudging a 442 Hz orchestral recording down, or correcting a sample that's 20 cents sharp. For those jobs, use a DAW or sampler with a fine-tune setting.

Where it does help is the bigger moves. As a song pitch changer it can put a track into a key that suits your voice, and as a vocal pitch changer it can move an acapella a few semitones to match another track. It also works as a pitch and speed changer, with a separate speed slider from 0.5× to 2.0×. Changing speed there also moves the pitch, which is how tape-speed drift happened in the first place. If you're shifting vocals, How to Pitch Shift Without Ruining Vocals covers how far you can push it.

It runs in your browser on a file you already have, and your audio never leaves your device.

Frequently asked questions

What is concert pitch?

Concert pitch is the standard tuning reference where A4, the A above middle C, is 440 Hz. It's also written A440 or A=440 Hz, and all other notes in standard tuning are calculated from it.

Is 442 Hz very different from 440 Hz?

Not much. 442 Hz is about 7.85 cents above A440, less than a tenth of a semitone. Many European orchestras use it, and it won't affect key detection.

Is 432 Hz tuning better than 440 Hz?

There's no good scientific evidence that 432 Hz has special effects on listeners. It's about 31.8 cents below A440, so it simply sounds slightly flat next to standard-tuned music.

Can Vocal Cut's Pitch Changer convert 432 Hz to 440 Hz?

No. The Pitch Changer moves in whole semitones from −12 to +12, and 432 to 440 Hz is only about 32 cents. Use a DAW or sampler with a fine-tune control for that.

Why does my key finder give the wrong key for an old recording?

Older recordings sometimes run slightly fast or slow, leaving them between keys. A key finder that assumes A = 440 Hz can split notes across two semitones when a track is far enough off, which blurs the result.