I read that a harmonica could be tuned in A441 plus, but I don't know what that means. How is this different than A440 tuning?

If you play guitar, when you tune your instrument, is it always A440? Are there good reasons for other tunings? How do you reason? I play a digital piano so I always use A440. But I did find this video:

  • 1
    Regarding the guitar, there are some guitarists/bands that tune to a different pitch. Most notably Pantera's Dimebag Darrell who tuned to 432~437Hz (depending on who you ask). Early Metallica and ACDC also occasionally tuned down by a bit, while Def Leppard tuned to a higher pitch on their album Pyromania. Rumor has it that most of those were due to bad tuning, though, rather than a deliberate decision.
    – user13400
    Jul 1, 2015 at 8:30
  • If that's the case then finding out by ear what they play must be more difficult. Is that the case?
    – user20754
    Jul 5, 2015 at 15:16

4 Answers 4


While A440 is the standard today (with a growing tendency to increase Hz by Hz in orchestra), it has not always been. In Renaissance and Baroque there was a wild variety of reference tones depending on the region, frequently 415 and even low as 391 Hz.

So obviously, if you want to play repertoire from that time, it is a consideration, to adjust the frequency to the one, which the composer may have had in mind (as far as known).

As soon as you want to play in an ensemble with authentic period instruments, the pressure towards these frequencies increases, since there are many instruments, which either can't be retuned at all or only in a very small range (e. g. recorder, portative organ).


If you play guitar, when you tune your instrument, is it always A440?

Usually, the tuners have settings for the Hz. You can choose 440 or 441 or something else. So, in order to correctly tune in A440 Hz, you have to set your tuner to that frequency. Usually, that's the default setting in tuners, and unless you change it yourself, you'll be tuning in A440.

A440 is the pitch standard.

How is this different than A440 tuning?

The A441 will sound different than A440. Not that different, but if two instruments play an A note and the first instrument is tuned in A440 and the second in A441, they will sound out of tune with each other.

Are there good reasons for other tunings?

You can try out some other tuning and see if you like it or not. But, if you play with other musicians, you'll have to tune in the same frequency. Unless you're going for some kind of experimental music.

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    Just for reference, the difference in cents is: 1200 * log2(441/440) = 3.93 cents. The exact limit of a "just noticeable difference" for pitches is somewhat nebulous and variable, but this seems to fall just beneath it, or perhaps at the limit (i.e. if you play two notes sequentially, one in each pitch, most people will probably be unable to tell a difference). You could probably hear a bit of buzz (from beat frequencies) if played simultaneously, and this is probably the reason for pitching it just slightly higher -- it makes the timbre sound "brighter", an effect that causes pitch inflation. Jun 30, 2015 at 23:27
  • @CalebHines - does that mean, then, that playing a song in a higher key also makes it sound "brighter"? Maybe that's why key changes occur in songs?
    – Tim
    Jul 1, 2015 at 15:19
  • @Tim That sounds like a good question to ask! See also: music.stackexchange.com/questions/10388/… Jul 1, 2015 at 15:35

"A440" means that the pitch "A" is defined as a note that vibrates at the rate of 440 times per second. The international scientific unit for cycles per second is "Hertz", abbreviated "Hz". So you would usually see it expressed as "A = 440Hz".

This standard of defining the note A as vibrating at 440Hz only came in to common usage a bit more than 100 years ago. Before that time, in different cities and nations and in different times in history, there were different pitches used as the standard. Some historical musical instruments were designed for other tuning standards and could not easily be made to play in A = 440Hz.

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    There are still, apparently, a couple of orchestras which tune to A doesn't=440Hz.Never found out why. A conductor's whim?
    – Tim
    Jul 1, 2015 at 5:48
  • In earlier music (baroque and earlier) the tuning was often a lower pitch, I think around a semitone (I don't know for sure.) This might be the reason for the non-standard modern tuning @Tim mentions?
    – Andy
    Jul 1, 2015 at 7:38
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    Actually, most non-440 orchestras seem to tune UP. Boston Symphony, New York Phil. =442. German and French also. Berlin Phil. =443 ! Ensembles playing Baroque especially will be down a semitone (ish) to 415.
    – Tim
    Jul 1, 2015 at 7:47

As pointed out in the video you posted, many instruments are tuned with some compromise built in for various reasons. The reason for tuning to a frequency other than A=440 can be different depending on the instrument.

Harmonica's are tuned to a specific key unlike a piano which is tuned so that it can be played in any key. The reason some harmonica players may prefer a slightly sharp tuning, is to compensate for their particular playing style. Those who blow more forcefully tend to create a different vibration pattern in the reeds which can cause the intended pitch to sound lower. So they compensate by using a harmonica tuned slightly sharp.

Many guitarists are joining a growing trend towards tuning their guitar to A=432 Hz instead of the standard A=440. Guitarist who choose to alter their tuning frequency from the standard A=440 Hz, often do so because they feel that it will sound better, or more pleasing or will be more harmonious with the natural vibration of the universe.

One problem with a guitarist choosing a non-standard tuning frequency, is that if he/she plays with instruments such as a piano or harmonica, the guitar will sound out of tune. So if the guitarist plans to play with other musicians, all instruments must be tuned to the same frequency.

Here is an article online that very thoroughly explains some of the theory behind the A=432 movement among guitarist. A-432 Guitar Tuning Theory

There are many other articles about this on line.

  • @Dave Thanks for the help on the edit brother. Yes I meant 432 - but it was late at night in my end of the world and my brain was shutting down. Jul 2, 2015 at 14:57
  • To be honest, A = 432 Hz isn't an equal 'relaxing' sound either. The idea of lowered frequency actually comes from a scientific pitch theory that gives the C sound 2<sup>n</sup> values:<br /> en.wikipedia.org/wiki/Scientific_pitch <br /> According to that, the A sound should have been even lower -- ~430.539 Hz. And answering to your question, some perfect pitched people may be fond of other frequencies than 440 Hz so they may tune the instruments differently for their private use.
    – user25926
    Jan 16, 2016 at 17:58
  • "Guitarist who choose to alter their tuning frequency from the standard A=440 Hz, often do so because they feel that it will sound better, or more pleasing or will be more harmonious with the natural vibration of the universe." - Yes I have heard of this nonsense. The most common description they give is that 432 is an integer multiple of the schumann resonance (which its not actually, its 428.something).
    – Khalian
    Jun 30, 2019 at 18:23

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