liba 0.1.15
An algorithm library based on C/C++
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A note frequency table. More...
Go to the source code of this file.
A note frequency table.
The basic formula for the frequencies of the notes of the equal tempered scale is given by
\begin{aligned} f_n = f_0 a^n \end{aligned}
where
\(f_0\) = the frequency of one fixed note which must be defined. A common choice is setting the A above middle C (A4) at \(f_0\) = 440 Hz.
\(n\) = the number of half steps away from the fixed note you are. If you are at a higher note, \(n\) is positive. If you are on a lower note, \(n\) is negative.
\(f_n\) = the frequency of the note \(n\) half steps away.
\(a = 2^{\frac {1}{12}}\) = the twelth root of 2 = the number which when multiplied by itself 12 times equals 2 = 1.059463094359...
The wavelength of the sound for the notes is found from
\[ W_n = \cfrac {c} {f_n} \]
where \(W\) is the wavelength and \(c\) is the speed of sound. The speed of sound depends on temperature, but is approximately 345 m/s at "room temperature." http://pages.mtu.edu/~suits/notefreqs.html