31 Dec
2021
31 Dec
'21
12:13 a.m.
Hey hey,
I'm currently working on something and need note/pitch quantisation to
predefined musical scales. Some research has almost entirely yielded such
features in DAWs and hardware modules that can do it.
Is there a type of algorithm typical method to achieve that in realtime? I'm
not averse to using lookup tables over the full MIDI range or possibly an
expected pitch range.
Any help or pointers are welcome.
Many thanks and best wishes,
Jeanette
--
* Website: http://juliencoder.de - for summer is a state of sound
* Youtube: https://www.youtube.com/channel/UCMS4rfGrTwz8W7jhC1Jnv7g
* Audiobombs: https://www.audiobombs.com/users/jeanette_c
* GitHub: https://github.com/jeanette-c
I believe
We all have one true love
Somewhere in this world <3
(Britney Spears)
31 Dec
31 Dec
12:34 a.m.
On 12/30/21 14:13, Jeanette C. wrote:
I'm currently working on something and need
note/pitch quantisation to
predefined musical scales. Some research has almost entirely yielded
such features in DAWs and hardware modules that can do it.
Isn't this mapping defined by a fixed logarithmic relationship?
Wikipedia says that the C note is 261.63 Hz,
https://en.wikipedia.org/wiki/C_(musical_note), and every other note
likewise is subject to the same formula.
Yuri
12:38 a.m.
Hello Yuri,
thanks for your quick reply. -- Yes, simple mapping of one MIDI note to a
frequency is easy, and the environment in which I work offers built-in
converters for that.
But, how to best quantise chromatic notes to a given musical scale like C
minor or B Dorian? I would probably need some method to do it for both MIDI
notes and in frequencies.
Best wishes,
Jeanette
Dec 30 2021, Yuri has written:
On 12/30/21 14:13, Jeanette C. wrote:
--
* Website: http://juliencoder.de - for summer is a state of sound
* Youtube: https://www.youtube.com/channel/UCMS4rfGrTwz8W7jhC1Jnv7g
* Audiobombs: https://www.audiobombs.com/users/jeanette_c
* GitHub: https://github.com/jeanette-c
I believe
We all have one true love
Somewhere in this world <3
(Britney Spears)
I'm currently working on something and need
note/pitch quantisation to
predefined musical scales. Some research has almost entirely yielded such
features in DAWs and hardware modules that can do it.
Isn't this mapping defined by a fixed logarithmic relationship? Wikipedia
says that the C note is 261.63 Hz,
https://en.wikipedia.org/wiki/C_(musical_note), and every other note likewise
is subject to the same formula.
Yuri
12:49 a.m.
On 12/30/21 14:38, Jeanette C. wrote:
thanks for your quick reply. -- Yes, simple mapping of one MIDI note
to a frequency is easy, and the environment in which I work offers
built-in converters for that.
But, how to best quantise chromatic notes to a given musical scale
like C minor or B Dorian? I would probably need some method to do it
for both MIDI notes and in frequencies.
Chromatic representation has several harmonics. The lowest harmonic
defines a basic note, higher harmonics (2X, 3X, etc) depend on what
instrument is playing, and by themselves don't define notes.
Mapping is strictly logarithmical, i.e. log(F) would have notes equally
distributed. One note and other note begins in the middle of such
interval. The rest is simple math.
Yuri
1:12 a.m.
On Thu, Dec 30, 2021 at 02:49:45PM -0800, Yuri wrote:
Mapping is strictly logarithmical, i.e. log(F) would
have notes equally
distributed. One note and other note begins in the middle of such interval.
The rest is simple math.
That would be true for 'equal temperament', which is more or less
tne standard for electronic instruments. But there are hundreds of
other temperaments.
In equal temperament a musical fifth would be the ratio 2^(7/12)
= 1.498307 and a third would be 2^(4/12) = 1.259921.
In natural or pythagorean temperament those would be 3/2 resp.
5/4 exactly. But of course such simple ratios are possible only
in a limited set of keys.
Which is why a lot of other temperaments exist. All of them are
some compromise between exact musical intervals and the ability
to play in any key. Organs for example are almost never tuned
in equal temperament.
--
FA
10:25 a.m.
On Thu, Dec 30, 2021 at 11:38:52PM +0100, Jeanette C. wrote:
But, how to best quantise chromatic notes to a given
musical scale
like C minor or B Dorian? I would probably need some method to do it
for both MIDI notes and in frequencies.
It sounds to me like you are asking for an algorithm that would decide,
for some input note or frequency that is not in the scale, which note or
frequency should be output.
For example: if the scale is C major, and the input is C#, then what
should the output be?
Reasonable answers might include C or D, because these are the closest
notes (i.e. have the smallest distance from input to output, along the
scale).
So, your algorithm could simply "quantize down" (yielding C in the
example). Or, alternatively, you might prefer an algorithm that simply
"quantizes up" (yielding D in the example).
But I think you - entirely reasonably - hope for an algorithm that gives
the most musical result, and you also hope that this might be a topic on
which prior research has established such an algorithm.
Is my understanding correct?
If so, I'm afraid I don't know the answer - but perhaps somebody else on
the list will know it.
Good luck!
10:40 a.m.
Hi Sam!
Dec 31 2021, Sam Kuper has written:
...
For example: if the scale is C major, and the input is
C#, then what
should the output be?
Reasonable answers might include C or D, because these are the closest
notes (i.e. have the smallest distance from input to output, along the
scale).
So, your algorithm could simply "quantize down" (yielding C in the
example). Or, alternatively, you might prefer an algorithm that simply
"quantizes up" (yielding D in the example).
But I think you - entirely reasonably - hope for an algorithm that gives
the most musical result,
No. I am looking for something that will yield a steady
result and I
don't mind which of the two. That is the behaviour found in such
scaling/quantising features on the hardware I know about. Think Novation
Launchkey Mk3, Arturia MiniBrute 2S. I haven't worked with any quantiser
modules in the eurorack world, that support scales, but I think they
also use a static mechanism.
...
Best wishes and thanks,
Jeanette
--
* Website: http://juliencoder.de - for summer is a state of sound
* Youtube: https://www.youtube.com/channel/UCMS4rfGrTwz8W7jhC1Jnv7g
* Audiobombs: https://www.audiobombs.com/users/jeanette_c
* GitHub: https://github.com/jeanette-c
I thought love was just a tingling of the skin <3
(Britney Spears)
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6 comments
4 participants
participants (4)
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Fons Adriaensen -
Jeanette C. -
Sam Kuper -
Yuri