Fundamental (in Hz) to a MIDI note
Posted by hordia on August 26th, 2007
Working to have audio-to-midi in NetworkEditor (CLAM) I needed to convert a fundamental frequency value to a MIDI note one.
I found some source code related with this in Voice2MIDI app, but was not explained at all, so looking for the reason of that formula I arrived at this:
Knowing about equal-tempered scale (check this) and 
Then, starting with:
It’s easy to arrive at this:
and then, also taking in account this mathematical relation::
the final formula looks like:
and a final c++ code like:
fund_midinote = round( 69. + log(fundfrec/440.)*17.31234 );
Related post: nictuku’s inverse formula (i.e. from MIDI to Hz) here “Translanting MIDI Notes to frequencies in the diatonic scale using the central A (440hz) as reference“.
, audio , c++ , CLAM , english , GSoC2007 , math , midi , music theory , programming , standards