help ! tricky music / math problem

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tape smoke
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help ! tricky music / math problem

Post by tape smoke »

i have never been good at math, I am trying to make a program that maps a sample to 12 pads and pitches it 11 times keeping the first sample unchanged. the command line switch uses a couple of different strech techniques, the current pitch setting i am using tunes the notes by +1 or -1 semitones, this is cool, however, this is the way the sp pitches, it just pitches the sample and leaves the bpm the same always.

I am working on a different command line switch that uses a play back speed percentage, instead of a semitone value.

0% is playback speed unchanged which is pad 1 .

100% is exactly one octave up so pad 13. i want to skip pad 13.

so heres my question, i need the playback percentages for pads 2-12

remember pad 1 is 0 % and 13 is 100%

this might be handy, if anyone can help i would be very greatful
http://people.bu.edu/scott/chromatic.html

maybe this will help too

33rpm = 0% 45 rpm = 35%
Last edited by tape smoke on Tue May 17, 2011 1:46 am, edited 1 time in total.
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tape smoke
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Re: help ! tricky music / math problem i am having.

Post by tape smoke »

here is the manual for pitch shifting with the audio editor i am using http://www.surina.net/article/time-and- ... aling.html
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Sinapse
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Re: help ! tricky music / math problem i am having.

Post by Sinapse »

captian crunk wrote:here is the manual for pitch shifting with the audio editor i am using http://www.surina.net/article/time-and- ... aling.html
yo I didnt read any of your attachments but if the increments are even the math is like this

100% / 12 pads = 8.33% per pad

if you were gonna pitch up it would be

pad 1 = 0%
pad 2 = 8.33%
pad 3 = 16.66%
pad 4 = 24.99%
etc adding 8.33% with each pad, the 12th pad would be like 91.66% if you start with pad 1 being 0%.
***Important to note that these percentages all apply the original value, don't write it so it takes the percentage of the previous pad***

you could pitch down the same way just making the sample pad 12 and reversing the algorithm (decreasing by 8.33% each pad)

hope that helps
tape smoke
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Re: help ! tricky music / math problem i am having.

Post by tape smoke »

cool man that helped alot. i only know how to work off the last number i think its not ok to just keep pressing = on the calculator ?

i ended up with 91.63 on the last pad is that to much drift ?
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tape smoke
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Re: help ! tricky music / math problem i am having.

Post by tape smoke »

ok here it is . thanks and sorry for being border line retarded when it comes to this, if anyone want to make GUI for this, you really should. but it works right now, do you think it would be better to save the samples to the card, and have a different naming system for up pitching and down pitching ..

http://unsatisfied.comxa.com/12levelsmpc.rar
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tape smoke
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Re: help ! tricky music / math problem i am having.

Post by tape smoke »

my algorithm sound out of tune, not bad but its pretty bad.

this is what im using


pad1 =0 %
pad2=8.33%
pad3 =16.66%
pad4=24.99%
pad5=33.32%
pad6 =41.65%
pad7=49.98%
pad8=58.31%
pad9=66.64%
pad10=74.97%
pad11=83.3%
pad12=91.63%


if these are ok , maybe i should go a few decimal points ?
all feedback is apreciated .
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Ill Green
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Re: help ! tricky music / math problem i am having.

Post by Ill Green »

If this is for the MPC 500, then I suggest you pm eimer @mpc-forums. That dude made a whole chart of what you asked and is mathematically oriented with using the MPC500 to uncover new uses. I'll try to dig up an old post of his but its not easy.
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Re: help ! tricky music / math problem i am having.

Post by Sinapse »

yo crunk if it's out of tune then maybe the percentages don't change linearly..that's why I said I didn't read any of the info, I was making a pretty big assumption that the increments are linear.
tape smoke
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Re: help ! tricky music / math problem i am having.

Post by tape smoke »

it all good man, thanks to your idea i have better knowledge how a chromatic scale works , but i still dont have it tuned good enough, here is so ratios that perfectly tune semitones, maybe someone can help turn them into percentages,

pad 1 . ratio 100 -
pad2 . ratio 94.387
pad3 . ratio 89.089
pad4 ratio 84.089
pad5 ratio 79.37
pad6 ratio 74.915
pad7 ratio 70.71
pad8 ratio 66.741
pad9 ratio 62.996
pad10 ratio 59.46
pad11 ratio 56.123
pad12 ratio 52.973

these are the pitch ratios to chromaticlly tune a sample 11 times, if anyone can help convert these to percentages, starting with pad 1 as 0%

i cant waste anymore time trying to tune this righht now, but hopefully someone can help solve this riddle.
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tape smoke
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Re: help ! tricky music / math problem i am having.

Post by tape smoke »

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tape smoke
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Re: help ! tricky music / math problem

Post by tape smoke »

im not to shure about using magical chakra scales right now, but i found a nother clue.
http://www.phy.mtu.edu/~suits/scales.html
Interval Ratio to Fundamental
Just Scale Ratio to Fundamental
Equal Temperament
Unison 1.0000 1.0000
Minor Second 25/24 = 1.0417 1.05946
Major Second 9/8 = 1.1250 1.12246
Minor Third 6/5 = 1.2000 1.18921
Major Third 5/4 = 1.2500 1.25992
Fourth 4/3 = 1.3333 1.33483
Diminished Fifth 45/32 = 1.4063 1.41421
Fifth 3/2 = 1.5000 1.49831
Minor Sixth 8/5 = 1.6000 1.58740
Major Sixth 5/3 = 1.6667 1.68179
Minor Seventh 9/5 = 1.8000 1.78180
Major Seventh 15/8 = 1.8750 1.88775
Octave 2.0000 2.0000


i bet there really is a simple way.
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tape smoke
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Re: help ! tricky music / math problem

Post by tape smoke »

yo i went with the sinapse idea, but i used 99.98 instead of 100.

so it the same thing just a little loose. it actually sounds good. like a real sampler would tune it to a keyboard. i can finally take a break of being a hardcore math nerd, and start pitching some shit. here is the newest working sp 12 levels auto pitch shifting algorythm and batch file.

http://unsatisfied.comxa.com/12levelsmpc.zip
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