# Cents vs semi-tones on guitar

I was wondering, since we can tune our guitars by cents we can make them sound anywhere close to the note we need. So we can have open A be not 440 but 448 for instance. What restrictions are there not to make it sound bad with other guitars which have A ~440. I assume you can have max 100 cent per note not to go close to a semi-tone?

So for instance if we have A 440 the what is A# Hertz? If we do -50 to +50 around that open A, will it still sound okay with other guitars which are almost 440?

For instance on one guitar A = 442 and on the other A = 467, will they sound okay together? None of my guitar players ever get to exactly 440 on open A.

The idea of this question may be slightly hard to grasp, but basically do the cents matter much? For instance I play on Detuned organ with all notes set to -20 cents and it seems to sound okay with guitar, while we checked that the guitar notes are ~ near the center on the digital tuner.

• It might depend on your sensitivity to tuning. My tolerance for roots & 5ths is about 10 cents before it really, really bugs me. 3rds can go further because of even temper vs blue. Sharp is more painful than flat. Feb 9, 2018 at 15:56
• IMO - way too broad and subjective to properly answer this question. Feb 9, 2018 at 20:28
• Some tunes sound better with just tuning or other tunings that are not equal temperament. Some songs are most easily played with the instrument tuned well away from the standard tuning, such as tuning a string a semitone or full tone sharp or flat. But it's always a good idea to tune the instrument pretty close to the way it should be for the piece of music in question. Feb 9, 2018 at 22:55
• I'm wondering - between two low notes a semitone apart, will the cents actually be smaller, than those between two notes with higher frequencies, given that the no. of Hz is much greater?
– Tim
Feb 10, 2018 at 8:50

For instance on one guitar A = 442 and on the other A = 467, will they sound okay together?

There will be a beat frequency of about 25 Hz between them, which would be annoying to most ears. So generally I think the best answer here is "no".

None of my guitar players ever get to exactly 440 on open A.

I'm not sure what you mean by "exactly", but it should be possible to tune an open A string to 110 Hz within 1 Hz (open A is actually two octaves below A 440). Tuning is a learned skill, just like playing, so it may be that your guitarists just have more to learn on the subject of tuning.

...do the cents matter much? For instance I play on Detuned organ with all notes set to -20 cents and it seems to sound okay with guitar, while we checked that the guitar notes are ~ near the center on the digital tuner.

In general, yes they matter a lot, but that doesn't mean that small differences in tuning are always audible or annoying. Being within 5 cents or so is probably fine for most people in most situations, but it really depends a lot. There are many situations where slight mistuning is a desirable sound. Robert Smith of The Cure would deliberately tune his guitars slightly off to get a more chorused and sad sound.

Cents and Hertz are two different scales. Hz increase exponentially between notes, while cents are a linear compression of the same increase.

There are 100 cents between any A and adjacent A#. But you can’t really make a similar statement in Hz. There will be a different number of Hz between A2 and A#2 and A3 and A#3.

Cents do matter. A great deal. They matter less in different contexts but they are pretty important.

If two notes are played in unison and they are 50 cents apart. Even someone with no musical training would be able to tell that something’s up.

As they get closer and closer they tend to sound fine. I find that most people are ok if unisons are under 10 cents apart if there is vibrato. If no vibrato then under 5 cents different people seem okay with.

When multiple instruments are playing multiple chords precision is much less of an issue. In a band setting if a single string gets about 10 cents off. Another band member might notice but the audience probably won’t.

• It's certainly true that you can't directly convert from cents to Hz, but it's worth pointing out that a 50 cent difference is always (approximately) a 3% difference in frequency. Feb 9, 2018 at 17:03
• Your last para., In two big bands I work with, we always tune to concert Bb - with the keyboards and a tuner, to at least get a level playing field (almost literally!) - even the guitar and bass use that datum point. So, it's pretty important.
– Tim
Feb 10, 2018 at 9:45