What are Scala tuning files?

[David Larsen]

What do they do?
I've stumbled upon people asking how to use Scale files, how to create them, how to import them in certain VSTs, etc. But I can't find anything about them, other than .zip libraries with thousands of them.
So what do Scale tuning (.scl) files do and how do I use them?

[Aroused by JarJar]

http://www.huygens-fokker.org/scala/

The program is free and exports a great number of different tuning file formats. .tun is the most commonly used. What these tuning files do is map midi note numbers to different frequencies than the standard 12 tone equal temperament.

You can use or make any tuning you'd like- 15 tones in an octave, no octave at all (7 tones within Phi for example), historical tunings for more authentic Baroque performance, Indian tunings so you can play a raga in an appropriate tuning, ancient Greek tunings, ad infinitum.

Outside of "ethnic" and historical or neo-historical music, unusual tunings sneak into film and multimedia performance music as well. Even if you use alternative tunings only as an occasional "effect", it is worth having the feature in your synths.

One of the primary motivations for the development of synthesizers in the first place was to be able to use alternative tunings. The Telharmonium, arguably the first synth ever, was built specifically to be able to play in Just Intonation (tuning according to the harmonic partials). The Theremin and other early designs were consciously designed not just to sound voice-like, but to have freedom of intonation, like the human voice, just as the original conception of rhythm machines was not to play 4/4, but to play bizarre new rhythms.

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[David Larsen]

Sidulacra and Aroused, Thanks for the detailed posts, I really appreciate the replies, but I still don't really get the basic idea.. sorry :-/
What good is 15 tones in an octave? I mean won't that just sound completely detuned? Or maybe that's the idea?

Do you perhaps have some examples of real life applications? I didn't know Harmor could use .scl files, but I just tried importing a few, and they just kinda made it detuned and impossible to play... Maybe that's because of the missing KBM files you mentioned Sidulacra, but I still don't get the principle.

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[David Larsen]

Again, thanks for the effort in trying to explain the concept to me, but pretty much your entire post went way over my head .

An analogy would be that you're trying to explain the math behind the aerodynamic properties inside a jet-engine to somebody who barely knows what a airplane is.

I think I need some demonstrations of practical appliacations or musical samples, if you don't mind. PM them if you prefer that

[nonoctave]

Again, thanks for the effort in trying to explain the concept to me, but pretty much your entire post went way over my head. An analogy would be that you're trying to explain the math behind the aerodynamic properties inside a jet-engine to somebody who barely knows what a airplane is.

Hey David, I can see that some of Sidulacra's terms sound unfamiliar. Maybe I can help a little.

You had asked about 15 tone equal temperament, meaning the interval of an octave equally divided into 15 equally sized chromatic steps, right? This in comparison to the popular 20th century western tuning of 12 tone equal temperament, meaning the interval of an octave equally divided into 12 equally sized chromatic steps.

One way to abbreviate 15 tone equal temperament is 15tET. Some people object to the use of the word temperament, questioning whether it is appropriate since tunings such as 15tET are not really descended historically from scales using tempered chains of fifths like the Baroque meantone temperaments were. So some use the term "15 equal". But 15 equal what? So some said 15EDO, meaning 15 equal divisions of the octave. But one can have equal divisions of intervals other than the octave, and the octave can be an exact frequency ratio of 2/1, or with pianos it can be somewhat stretched, so to clear things up some use ED2, meaning equal divisions of the exact 2/1 interval. So 15ED2 is just another way to say 15 tone equal temperament, or 15 equal divisions per octave.

With cents, that is a very important unit used to specify intervals regardless of whether one is involved in microtuning. Many ethnomusicological studies use it, and it's used as a parameter in many synthesizers for oscillator detuning and other uses. Even if someone never wants to do anything but 12tET, they should know cents. The interval of the octave is divided into 1200 equal units called cents. There are 100 of them per 12 equal tempered semitone. The measurement is intrinsically 12tET centric, but it's quite the standard and well worth being familiar with.

For example, the purely tuned pythagorean fifth interval of 3/2 is about 2 cents sharp at around 702 cents, whereas the 12 tone version of the fifth is at 700 cents since it spans seven equal tempered semitones. A cent is a pretty small tuning difference, so you can surmise that in 12tET the fifths are pretty close to pure or justly tuned where a timbre with harmonic overtones is not going to display any beating. But the major third on the other hand the commonly used just tuned version is a frequency ratio of 5/4. This turns out to be about 386 cents, which is 14 cents flat of the 400 cent version in 12tET. This is a pretty big difference so you might guess looking at the cents values that the thirds in 12tET are harsh and beat a lot compared to the just version and you'd be right.

[Nystul]

In modern times we usually use equal temperament. What this means is that the distance from C to C# sounds the same as the distance from C# to D or any other half step. Each octave has 12 notes a half step apart, so we call this 12 tone equal temperament. This is kind of the standard and default tuning for today. If you go back in time a few centuries, they still had keyboard instruments with 12 keys per octave, but they did not tune each note an equal distance from the others. There were subtle differences depending on which interval it was, in order to make the most common harmonies sound closer to perfect. So microtuning can be used to imitate what they did historically, which is slightly different from our current tuning. Also, acoustic pianos are actually tuned with wider than normal octaves, so microtuning could be used to imitate that. Music from other parts of the world does not use our Western scales with 12 equally spaced notes, so microtuning could be used to more accurately recreate those types of music. Or maybe someone just has some weird musical ideas that don't fit 12 tone equal temperament. So those are some reasons.

To try to explain a bit more about intervals, our concepts of harmony is based on the idea that notes have overtones which vibrate at multiples of the main frequency. For example you could have a sine wave synth bass with content just at 60 hz, but a real life bass instrument would have quite a bit of harmonic content at 120 hz, 180 hz, 250 hz, and so on for the 60 hz note. If the harmonic content were distributed more randomly instead, then you would have more of a unpitched noise rather than a pitched tone. Anyways, because of this relationship, rich harmonies were created using notes with closely related frequencies. You have the just octave, where the high note is double the frequency of the note below it. You have the just fifth, where the note is 3/2 times the frequency of the low note. It keeps expanding along those lines, and those were kind of the ideas that they were trying to get close to with the historic tunings.

[David Larsen]

Hey David, I can see that some of Sidulacra's terms sound unfamiliar. Maybe I can help a little.

equal temperament
chromatic steps
Baroque meantone
ethnomusicological
tempered chains of fifths

As much as I'd love to understand all this....... Well, even after having looked up every single term you all used, and re-read all 3 pages of text you guys have written for me so far, I still can't understand what all this is good for.
Sorry if I'm being impossible, I know it can be frustrating to try and explain something to somebody who just doesn't get it

Maybe I'm just simply in way over my head, and it's simply a matter of ME trying to understand the math behind the aerodynamic properties inside a jet-engine, when I should really just be focusing on the airplane


I really think I need a practical example... Let's say you imported tuning scale X into a synth. It's there, it's all set up, and it works. What now? What would you do with it? How would you make it sound good, and why would it be better at X than whatever is the default, standard, normal, good-sounding, pure a-a#-b-c-c#-d-d#-e-f-f#-g-g# scale that we all know and love?

[Aroused by JarJar]

I really think I need a practical example... Let's say you imported tuning scale X into a synth. It's there, it's all set up, and it works. What now? What would you do with it? How would you make it sound good, and why would it be better at X than whatever is the default, standard, normal, good-sounding, pure a-a#-b-c-c#-d-d#-e-f-f#-g-g# scale that we all know and love?

There is no need to understand any math. The synthesizer needs to math description of a tuning, we just need to hear it.

Well the answer to your question is that some people think music is about "feeling" and "emotion" and "evocation" and things like that. If music is about feelings and images etc, of course you don't use just one symmetrical historical tuning. That would be like a law making all painters use only a single small palette of the same fixed colors.

The most obvious example in more modern times is the blues. Why didn't the blues musicians stick to 12-tET, why did they use all those "out of tune" "blue" notes? For "emotion" of course.

Now here's the thing about "in tune" and "pure": 12-tET is not "pure". It is a mathematical compromise of detuned intervals. It took literally centuries for 12-tET to become standard, because people were kicking against the impure (beating, dissonant) thirds and sixths. Many people are into alternative tunings because they want actual pure intervals, which means intervals in tune with the natural harmonic series (the overtones in the human voice, string instruments, woodwinds, etc. etc.). There are whole musical cultures built around this, in historical performance circles, New Age, etc.

Music entirely in tune with the natural harmonic series has very noticeable effects, especially in live performance. Our 12-tET is acoustically not pure and beats/buzzes a lot. Some people loathe music in acoustically pure tunings. The absence of buzzing between the partials can have a soporific effect, which drives some people up the wall. Others find it soothing, even "healing". "Healing" is not a falsifiable claim and can't really be judged scientifically, but buzzing and beating are concrete measurable predictable phenomena, and whatever other numerological mumbo-jumbo goes along with it, it is empirically true that "Just Intonation healing music" is indeed "more mellow" on a physical level (far less psycho-acoustic beating, plain and simple).

Anyway, what if we do not care to have everything acoustically pure? I like beating and buzzing, so why not use 12-tET? Well, there's that emotion thing. 12-tET has a major third, and a minor third, and these are generally important in evoking different emotions. But I don't feel in black and white, and no matter how much you combine and contrast major and minor, and no matter what timbres you use, you never ever get the emotional evocations of the thirds that are in between major and minor. All of the near and middle East (and traditionally the outer edges of Europe) use these "in between" thirds. They have different emotional potentials. So right there, that alone, is enough to use alternative tunings.

I prefer musical exchange in physical life, but I made some brief examples- any synth and sound design examples I post here are going to be in alternative tunings.

For an "analog brass" discussion I made this "swords and sorcery" kind of thing, happens to be tuned according to ancient Greek systems, roughly in 17 equal:

http://www.mediafire.com/?5ewp5l8m2io5f0z

this tuning is based on a "natural tritone", with grievously detuned octaves, such that whatever you play, it goes together, but is always acoustically dissonant:

http://www.mediafire.com/?iu75wkvmg7n1xrg

and this is in 16-equal, which is a great tuning because it is full of more or less mellow intervals, and familiar-sounding intervals, but has no fifth! It is impossible to do conventional chord progressions. For me this tuning has all kinds of familiar-yet-strange evocative possiblities.

http://www.mediafire.com/?dml7ow6zzbxcvjg

[Aroused by JarJar]

Heh- thought I gave a simple, non-technical and straightforward reply there.

Pitch is just another dimension of music, and we use different kinds of pitch relationships just like we use different rhythms, sounds, words in songs, etc, and for the same reasons: feelings, emotions, evocations of atmospheres and ideas, etc etc.

That is all there is to it, really.

[memyselfandus]

"There is an unfortunate trend that's been happening in microtonal software design for sometime now, where developers are implementing only the SCL part of the format and leaving out the KBM entirely. Synths that have this critical design flaw typically map every microtuning with its 1/1 on 60.C and the Reference Frequency also on 60.C with a frequency of 262 Hz. This is basically useless for any serious work with alternative intonation systems, because inevitably, and for myriad reasons, musicians and composers will want complete control over these musically important parameters.

All Cakewalk instruments that use the SCL format, and now Image Line's Harmor, have this design flaw.

What this means in plain English is that the user cannot set up a full-controller microtuning which maps specific pitches to MIDI Note Numbers in the way that the TUN or MTS format can, and users will have to accept that everything will be on C, unless they are prepared to change the master tuning reference, and or, offset the pitches of the instrument oscillators.

This trend in developing and publishing these tools with this microtuning design flaw is compounded by the fact that there is no information available to developers about how to correctly implement the SCL/KBM format, and the only developer that seems to have a correctly functioning implementation is Modartt with their Pianoteq plugin."

WOW this is good information. Anyone know what other plugins fail to have the full and correct options for microtuning? and which plugins Do in fact support it? Pianoteq is awesome.

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[memyselfandus]

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[jancivil]

why would it be better at X than whatever is the default, standard, normal, good-sounding, pure a-a#-b-c-c#-d-d#-e-f-f#-g-g# scale that we all know and love?

By that I guess you mean 12 equal steps per octave, 'semitones'.

the reason for that choice is all about a compromise. there wasn't always the ideation that you needed to have 12 major and 12 minor keys at hand. What worked harmonically, ie., what was a 'good' concord for C got progressively less so as you go around the circle of fifths in the older temperaments.

EG: let's begin at C as it is a simpler conception at the keyboard for our purposes.
If you sound a strong C in a bass, ie., to generate more harmonics...



one of the things that you find is that fifth partial. That is a natural occurrence, and musically we think of that as the major third. You see a '-14' above it in the image. That chart is the overtone series compared to equal temperament. This means that the equal tempered, 12 to an octave you actually referred to as 'pure' is ~14 cents (14 per cent of one of the 12 divisions) sharp. It's that 'impure'. IE: a body is not likely to arrive at the ET interval as it vibrates differently than if you arrived at the 'just' interval.

Instrumentalists that can obtain this simpler concord (eg., non-fretted strings, wind instruments) will seek to do so by adjusting while dealing with the written note or what-have-you.