educate me on a lil bit of musical math

[Guest I'm Too Cool To Have An Avat]

I know A-4 (or was it A-5?) is a perfect 440hz (or is that khz?) sound frequency, the only one I know of that's a nice integer without ugly little decimals trailing after it.

 

That said, is there a simple mathematical function to compute the frequency of any note that's (+-)x halftones away from A-4 as a center? I understand music notes are on a somewhat logarithmic scale, so it's probably more complicated than just adding or subtracting a multiple of certain number from that.

[plastic]

440*2^(x/12), where x is the amount of semitones you wish to transpose from A.

[plastic]

 

or you can just use these nice tables I made a couple years ago.

[kcinsu]

or

 

f x 1.0594631

 

f is the frequency of the current pitch, say, 440hz (A4), and when you multiply it by that number you get the next semi tone up (A#4)

 

divide to get the next semitone down

 

 

 

or his nice tables

[Guest I'm Too Cool To Have An Avat]

Thanks guys

[plastic]

or

 

f x 1.0594631

 

f is the frequency of the current pitch, say, 440hz (A4), and when you multiply it by that number you get the next semi tone up (A#4)

 

divide to get the next semitone down

yeah... you'll find 2^(1/12) = 1.0594630943592952645618252949463

 

using a variable for the numerator is just a little short cut.