Re: [sc-users] Playback rate to semitones

[eli.fieldsteel@xxxxxxxxx]

You can use the midiratio method:

12.midiratio; //—> 2

The math involves multiplying the starting frequency by 2 raised to the power of n/12, where n is the up/down semitone shift. 

Eli

On Wed, Jan 9, 2019 at 10:11 AM <kennethflak@xxxxxxxxxxxxxx> wrote:

Just got stumped trying to figure out a conversion between playback rate and semitones. Given that playing back a sample at a rate of 0.5 will transpose it down 12 semitones, and playing it back at 2 will transpose it up 12 st... How do I calculate arbitrary semitone transpositions up and down in terms of playback rates? My math part of the brain is apparently not working today. 

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_______________

Eli Fieldsteel, DMA

Director, University of Illinois Experimental Music Studios 

Assistant Professor of Composition-Theory

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