[music-dsp] octave numbering + semitone numbering

Johan Boulé Johan.Boule at Online.Fr
Sun Mar 11 19:52:49 EST 2001


Phil Burk wrote:
> James Chandler Jr wrote:
> > >     semitone number 60    is 523.25Hz (middle C)
> >
> > That semitone numbering system is identical to the MIDI standard. Middle C
> > is MIDI note 60.
>
> Sorry. Middle C is MIDI note 60 BUT it is 261.626 Hz (not 523).
> This is true regardless of whether you consider Middle C to be C3 or C4
> or C5.
>
> Concert A is MIDI note 69 and is 440 Hz.

I'm disapointed, because, since middle C is defined by being a the middle of a piano keyboard, it should be near the middle of the
audible spectrum (523.25Hz is near 632Hz). Keyboards can cover more or less octaves, but should at least be centered in the audible
spectrum: we don't speak about "bass pianos" or "high pianos".

If i don't make any mistake, the highest note number for MIDI is 127, thus, if 440Hz is note number 69, then note number 127 would
be 12543Hz only, which is far below the highest audible frequency.



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