11 Dec
2005
11 Dec
'05
6:23 p.m.
Atte André Jensen wrote:
Hi
Suppose I have an A with a frequency of 440 hz. Which formula should I
use for transposing x semitones up/down? So which frequency would the
Bb a half step higher for instance have? What about cents (1/100's of
half steps)?
You know that every note has a frequency which is twice the frequency of
the same note an octave below. You have too go from the A at 440 hz to
the A at 880 hz with 12 equal steps. So, for each semitone you have to
multiply the frequency of the previous note by the twelfth root of two
(approx. 1.059463094).
See:
http://en.wikipedia.org/wiki/Twelfth_root_of_two
c
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