Jeepers creepers!
 
Let me take some of this stuff in for a bit... So much to read LOL!!! 

For my post it is probably easier to scroll to my conclusion and try to work through the step by step then go back and try to figure out the rest of the stuff I was blathering about. Might more sense getting it under your fingers first and then going through the reasons WHY it all works that way.
 
I should have edited it more too to make it more concise/lucid but yeah... lots of typing. Bored now. SQUIRREL!
 
BTW... you should also take a stab at learning the concept behind the Circle of Fifths. It helps translating all this crap to all 12 keys. I would normally recommend learning how the 7 natural modes work, then the Circle of Fifths then moving on to the Harmonic and Melodic minor.
 
I've got reams of stuff written about the CoF but it's not really in proper lesson format yet.

Music theory is a tool - a fascinating tool if you like math and music - but it remains but one tool in a wide array of tools.
 
There are dozens of ways to learn scales. I teach my students the major scale as a pattern of half and whole steps (WWHWWWH) and then I move them to the circle of fifths. The combination seems to reinforce the concept of scale construction, and most of them rapidly reach the point where they can construct any major scale in their heads without any real effort.
 
Next I introduce the seven Greek modes. No, I'm still not sure why, but it seems to work for most students. Again we learn the pattern for each mode, and then we apply the circle of fifths again, although by this point most of them simply add these to their vocabulary.

And once they know the Aeolian mode they also know the natural minor scale. Adding the harmonic and melodic variations seems to come somewhat naturally from there.
 
Some of this is just plain brute memorization, but there are lots of patterns, some of which will make sense to some folks, while other folks will find different patterns.
 
Now let's see how well my pattern memory is working today - I've listed what I think are the more important scales, and the Greek modes below. I've included the number of sharps or flats, which scale tones are altered, whole and half steps, and the names of the notes starting on "C".
Major / Ionian 1 2 3 4 5 6 7CwDwEhFwGwAwBhCLydian1 [class="font5"]♯1 2 3 #4 5 6 7CwDwEwF#hGwAwBhCMelodic Minor (ascending)1 [class="font5"]♭1 [class="font0"]2 [class="font5"]♭[class="font0"]3 [class="font0"]4 [class="font0"]5 [class="font0"]6 1617CwDh♭EwFwGwAwBhCMixo-Lydian1 [class="font5"]♭1 [class="font0"]2 [class="font0"]3 [class="font0"]4 [class="font0"]5 [class="font0"]6 [class="font5"]♭3233CwDwEhFwGwAh♭BwCHarmonic Minor2 [class="font5"]♭1 [class="font0"]2 [class="font5"]♭[class="font0"]3 [class="font0"]4 [class="font0"]5 [class="font5"]♭[class="font0"]6 5051CwDh♭EwFwGh♭AwhBhCDorian2 [class="font5"]♭1 2 [class="font5"]♭[class="font0"]3 [class="font0"]4 [class="font0"]5 [class="font0"]6 [class="font5"]♭6667CwDh♭EwFwGwAh♭BwCNatural Minor /Aeolian3 [class="font5"]♭1 [class="font0"]2 [class="font5"]♭[class="font0"]3 [class="font0"]4 [class="font0"]5 [class="font5"]♭[class="font0"]6 [class="font5"]♭8687CwDh♭EwFwGh♭Aw♭BwCHalf Diminished4 [class="font5"]♭1 [class="font0"]2 [class="font5"]♭[class="font0"]3 [class="font0"]4 [class="font5"]♭[class="font0"]5 [class="font5"]♭[class="font0"]6 [class="font5"]♭108109CwDh♭EwFh♭Gw♭Aw♭BwCPhyrigian4 [class="font5"]♭1 [class="font5"]♭[class="font0"]2 [class="font5"]♭[class="font0"]3 [class="font0"]4 [class="font0"]5 [class="font5"]♭[class="font0"]6 [class="font5"]♭130131Ch♭Dw♭EwFwGh♭Aw♭BwCDiminshed / Locrian5 [class="font5"]♭1 [class="font5"]♭[class="font0"]2 [class="font5"]♭[class="font0"]3 [class="font0"]4 [class="font5"]♭[class="font0"]5 [class="font5"]♭[class="font0"]6 [class="font5"]♭154155Ch♭Dw♭EwFh♭Gw♭Aw♭BwCAltered6 [class="font5"]♭1 [class="font5"]♭[class="font0"]2 [class="font5"]♭[class="font0"]3 [class="font5"]♭[class="font0"]4 [class="font5"]♭[class="font0"]5 [class="font5"]♭[class="font0"]6 [class="font5"]♭180181Ch♭Dw♭Eh♭Fw♭Gw♭Aw♭BwCSome folks prefer to think of the modes as "all the white keys starting on...", which is fine if you are used to the piano keyboard. Many of my students only play guitar, so I try not to emphasize white and black keys<G>!
Major / Ionian 1 2 3 4 5 6 7CwDwEhFwGwAwBhCDorian2 [class="font5"]♭1 2 [class="font5"]♭[class="font0"]3 [class="font0"]4 [class="font0"]5 [class="font0"]6 [class="font5"]♭196197DwShFwGwAwBhCwDPhyrigian4 [class="font5"]♭1 [class="font5"]♭[class="font0"]2 [class="font5"]♭[class="font0"]3 [class="font0"]4 [class="font0"]5 [class="font5"]♭[class="font0"]6 [class="font5"]♭218219EhFwGwAwBhCwDwELydian1 [class="font5"]♯1 2 3 #4 5 6 7FwGwAwBhCwDwEhFMixo-Lydian1 [class="font5"]♭1 [class="font0"]2 [class="font0"]3 [class="font0"]4 [class="font0"]5 [class="font0"]6 [class="font5"]♭236237GwAwBhCwDwEhFwGNatural Minor /Aeolian3 [class="font5"]♭1 [class="font0"]2 [class="font5"]♭[class="font0"]3 [class="font0"]4 [class="font0"]5 [class="font5"]♭[class="font0"]6 [class="font5"]♭256257AwBhCwDwEhFwGwADiminshed / Locrian5 [class="font5"]♭1 [class="font5"]♭[class="font0"]2 [class="font5"]♭[class="font0"]3 [class="font0"]4 [class="font5"]♭[class="font0"]5 [class="font5"]♭[class="font0"]6 [class="font5"]♭280281BhCwDwEhFwGwAwBThe other thing to memorize, or figure out anyway, is the circle of fifths, which looks way cooler in graphic form, but here it is in tabular format - with relative minor scales to boot!
C Major0A MinorG Major1 #E MinorD Major2 #B MinorA Major3 #F# MinorE Major4 #G♭MinorB Major5 #D♭MinorF# Major6 #A♭MinorG♭Major6♭E♭MinorD♭Major5♭B♭MinorA♭Major4♭F MinorE♭Major3♭C MinorB♭Major2♭G MinorF Major1♭D MinorThat ought to get you started<G>...
 
Bill

Blimey... I've got to get off my computer now. I've managed to read through Bob's and Beep's posts, but not Bill's.
 
I'm going to have to make a few trips back to this and I am more than likely going to copy/paste to a word doc or something so I can format and print, or read offline. But, I promise, I will let peeps know how I'm doing...
 
I should also perhaps explain that I've been reading a bit of theory over the years... I just don't stick at it and then stuff that I have learned leaks out of the old brain cells again.
 
Books I have are:-
 
The AB Guide to Music Theory parts I and II, by Eric Taylor (I've had these for years)
 
and The Encyclopedia of Picture Chords for Guitar and Keyboard (pictures always help hahaha)
 
I've also stumbled across this website, which is really helping me:-
 
https://www.basicmusictheory.com/
 
So, yeah... I really appreciate the posts here and as soon as I can get back to my 'puter I'll post some more thoughts, including the reason that prompted to post this in the first place (I've got a chord progression I'm working on and I'm coming unstuck with playing over the top, or if even the progression is a "valid" one).
 
 
cheers
 
andy 

All chord progressions are "valid" if you use the chord to chord approach to melody. Essentially you just set your key/mode up for each chord. Many times you can traverse multiple chords using the same key but when you stick in a chord that doesn't appear in that key you change it up.
 
The opposite of this action is choosing varying modes to play over top of the same chord in a progression which again is setting up a new key.
 
To effectively do either of those things though you of course have to learn about keys, the possible modes within in each and what scales within all that fit over top of which chords.
 
That's why I personally think it's best to become proficient with the natural modes starting in C Major then being able to understand and use the Circle of Fifths to easily construct it all in any key. From there basic chord study is simple (the 7 triads and then 7th chords).
 
THEN making the slight alterations to the modes like we do with Harmonic and Melodic minor and understanding how those alterations change the landscape of the modes and chords therein becomes a lot less daunting.
 
That's not to say you can't toss in those scales if they happen to sound good but you won't understand WHY it sounds good and it'll be kind of trial and error as opposed to calculated tonal decisions.
 
Cheers.

And if all this isn't enough, once you get your head around the "Western" modes and scales you can move on to the many other scales from around the world which are outside that system. :-)
 
Even in Western music there are scales such as the well known "blues scale", the many variations of  which fall somewhere between major and minor but are played against major harmonies.
 
The key thing to remember, and all that really matters, is that if it sounds good it is good and unless you're taking an exam that penalises you for theoretical "mistakes"* never let adherence to musical theory get in the way of good sounding music.
 
*the common or garden roots and fifths "power chord" shifting up and down a guitar neck that propels much of modern popular music being an example - in Western classical theory "consecutive octaves" or "consecutive fifths" are hugely frowned upon as "weak".

tlw
And if all this isn't enough, once you get your head around the "Western" modes and scales you can move on to the many other scales from around the world which are outside that system. :-)
 
Even in Western music there are scales such as the well known "blues scale", the many variations of  which fall somewhere between major and minor but are played against major harmonies.
 
The key thing to remember, and all that really matters, is that if it sounds good it is good and unless you're taking an exam that penalises you for theoretical "mistakes"* never let adherence to musical theory get in the way of good sounding music.
 
*the common or garden roots and fifths "power chord" shifting up and down a guitar neck that propels much of modern popular music being an example - in Western classical theory "consecutive octaves" or "consecutive fifths" are hugely frowned upon as "weak".

I've found that almost without fail that, aside from symmetrical scales, pretty much all of those combination and foreign scales fit into/can be defined with modal theory. You just add or remove a note here or there and it'll fit inside of either the natural, harmonic or melodic modes. Then you can easily use the same framework of those to easily navigate, write in and transpose all the weird stuff.
 
Perfect and obvious example is Mixo-Blues which of course is mixolydian with some extra awesome tossed in and you can treat it as such. You can also pretend like it's Dorian with extra notes and come at it from another angle. All like an awesome jigsaw puzzle that can be fit together in many MANY different ways.
 

Few, that is a lot of words.  I don't have the time to read all of it but to add just a little insight to simplify the process from a music theory teacher.  
 
Harmonic Minor- Use for Harmonies.
Melodic Minor- Use for Melodies.  
Natural Minor- Don't use.
 
At least that is the historical context of the scales.  Why?
Because of the importance of the leading tone, or the 7th in major.  It is an essential relationship for establishing a key center for all melodic and Dominant V to Tonic I chord progressions.  v-i is rare V-i is not.
 
Natural minor does not contain a leading tone, so it is not a musical option, it is just a key signature reference "scale"
 
As to melodic minor: In any scale form, ascending to the tonic which requires a rout through the 7th, must contain a leading tone, (not a subtonic, which is what a flat 7 is called) .  BUT!!!  You must also be aware that augmented intervals were rarely if never used, so 6-flat to 7-natural, an augmented 2nd, is out of the question.  To compensate, we also make 6 natural ascending so the melodic line avoids the augmented interval.  Descending does not matter if the plan is to move away from the tonic, so flat 7s and 6s are fine.  
 
Harmonies don't suffer from the needs of a moving line, so only the strong leading tone is kept in "Harmonic" minor. 
 
It is rather silly to see these as forms of scales rather than tonal relationships in the music, as the only minor mode suitable for a stepwise line is melodic.  You will not encounter many harmonic minor melodies outside of modern music and awful Egyptian stereotype music.    
 
 

I respectfully yet completely disagree. That's the traditional way and it completely shuts out whole universes of musical possibilities. Of course much great music has and will continue to be created using that school of thought but there is no reason to dismiss everything outside of it. It hurts the art as a whole IMO. It is also much more difficult to grasp the bigger picture due to its rigid and exclusionary nature.
 
Of course I would never discourage anyone from learning those concepts. They are useful.
 
BTW... I use natural minor all the time for melodies and improv. It's kind of the default mode of metal and sounds great over all kinds of other music. Nothing wrong with nat minor. It can also be easily transformed into melodic or harmonic minor or any of the minor modes too for mixing up an improv.
 
Also, having listened to some of synkro's compositions, he strikes me as a "modern" music type of dude.
 
I do completely respect the fact you have learned the formal methods to the point of elevation to instructor status. That ain't easy. I just scour dusty old theory books to compare and test my own theories with the "proper" way. None have failed so far (unless I made a mathematical error).

Is always interesting to see folks insights into things. I admit I did not read through this entire thread, but wanted to throw out a quick minor tip... rather than learn three scales, only learn ONE... let me explain...
 
First a quick background... Take a major scale (I am happiest in Gmaj so will use that), make the 6th of your major scale the new tonal center, and you get that natural minor with the same notes. Because of the natural 7th leads into the octave most easily, the "harmonic" minor does this, but leaves a 3 half-step jump that throws of singers... so the 6th was also raised to "ease the jump" (when ascending only) which is the "melodic" minor. For all three scales, the first->fifth are identical.
 
So... we have made Gmaj into Emin (natural) by simply starting on E with the same notes (E, F#, G, A, B, C, D)
 
only the 6th and 7th change... so play this until the tones "sink in"...
 
B->C#->D# (melodic ascending) ->C->B (harmonic descending)
 
The only variation of the natural minor occurs on those notes (and in that ascending/descending pattern), so is no "need" to learn "3 scales," since they is truly only one with variation on application.