Chords, scales, harmony, melody, etc.
mattrix3
KVRer
22 posts since 1 Dec, 2021
I'm a rank beginner so please take it easy with the jargon and acronyms.

We hear the terms in the title all the time, but I'm not sure what they are. They seem to be used interchangably, and often defined circularly.
I can not see the difference between a mode and a scale.

What I have found is,
A mode is the pattern of an ordered list of the notes in a key.
A scale is the pattern of an ordered list of the notes in a key.
Some modes are scales.
What is the criteria to elevate a mode to a scale?

A key is the set of notes in an anchored scale (or mode).
There is a mode-group of 7 rotationally related modes for each key.

Related modes, keys and scales all contain the same set of 7 notes??

So I asked myself 'How many selections of 7 notes are there'?
I define a selection as having 1 variety from each of A,B,C,D,E,F,G.
AND
adjacent notes are 1 or more semitones apart.
(this latter avoids things like B# and C, A# and Gb in the same selection)

Using this definition I came up with 168 'selections', each with 7 modes.

Are these selections keys? Some of them?
What is the criteria to elevate a selection into a key?

Looking at the patterns of the notes in these selections I can identify 40 mode-groups.
A selection implies 1 mode-group. However a mode group can be implied by many selections.

So I have selections and mode-groups whereas you have keys and scales.

Can someone help me sort this mess out?
Do we have 40 scales? Which of the possible scales are rejected? Why?
Because of the selection process, each selection could have a unique key signature. Are all of these valid? Why?
etc

jancivil
KVRAF
23649 posts since 20 Oct, 2007 from gonesville
a mode scarcely needs elevating to be what it is, a scale form. Once upon a time there was no major v. minor paradigm, at this time scale was strictly from modes

Modes haven't keys. C Dorian Mode, for instance, given a key signature uses the one from Bb major, but C mode is grounded on C, not Bb.
A key is a major or minor key, there are 12 each. End of story.

Any scale may be 'modalized'. So you have say C D Eb F G Ab B (C Harmonic minor), you can reconsider this set founded on F. In such a case this is called the fourth mode of C Harmonic minor. Satie's Gnossienne 1 uses this for the tune.

Who's rejecting scales? I'd suppose the why of that accounts for taste. I wouldn't worry about how many, you can make your own out of any intervallic material. Less than 4 is maybe not much of one...

In 20th century practice, people would write a key signature up for their scale. G melodic minor ascending, not terrifically exotic, would feature one flat and one sharp then. And the experienced musician reading would have a specific clue of the exact set at once. It would make maximal sense for '4th mode of G melodic minor' should one decide it needs signing as though a key.

'what is valid' tends to get superseded by new concepts

mattrix3
KVRer

Topic Starter

22 posts since 1 Dec, 2021
Thank you,
So there are 24 keys, but 168 key signatures?
What makes a key major or minor?

Having a bit of troule interpreting. I have seen at least 2 ( & I think 3) definitions of Dorian mode.

Isn't it equally true that given G Ab B C D Eb F that the 4th mode of this is C Harmonic minor? There needs to be some convention for which is the root mode (scale?).

I have not considered how moving things up and down (transposition) affects things yet.

Baby steps.

shawshawraw
KVRist
338 posts since 4 Aug, 2020 from Montreal, Canada
Woah this thread needs math... My two cents:

To me "key signature" means a part we read from musical staves - the "#"s and "b"s on the leftmost of the staff immediately to the right of the clef sign. And there are 15 of them: no sharps or flats, 1 to 7 sharps, and 1 to 7 flats. I remembered I spent time memorizing the fixed order: F# C# G# D# A# E# B#, Bb Eb Ab Db Gb Cb Fb.

Looks like Wikipedia agrees me on this: https://en.wikipedia.org/wiki/Key_signature

Let's say you have a single sharp on the stave, which is F#. Let's say there's no accidental sharps or flats on all the notes. So the song is composed of the set of notes C D E F# G A B. Now, classically (and in majority of cases) the song is either in G Major or E minor. And we do say the song is in key of G or in key of E minor. But which one? It depends on if the G note has that "home" feeling or E note. The progression of notes will suggest this. However, there's a more important clue that the classical period has established, which is the V to I (five to one, dominant to tonic) movement.

The V to I movement typically happens on the last 1/4 of phrases when you listen to classical, as well as the grand finale of a longer piece, where you feel a strong resolution and satisfaction as it concludes - which most probably also pleased the audience at that time, the royal families. And this movement naturally works in a Major key. Minor keys can be harmonically tweaked to achieve this, albeit the different whole/half-step sequence than Major keys. I'm not sure if the classical composers ever tried basing a set of notes on a different "home" note, but most probably it didn't work or didn't sound good enough in achieving this V to I thing.

"Mode" is a concept where a piece of music does not feature the above mentioned kind of resolution. And church music actually started from it, which happened before the classical period. The seven names, Ionian, Dorian, Phrygian, Lydian, Mixolydian, Aeolian, Locrian, are originated from that era if I'm correct. When you don't have that "finale" feel, modes are sounding more stationary and clinging to a specific sonic colour, which is in fact really good for today's dance music, for example

"Scale", to me, is a super duper flexible concept - a set of whatever notes that I can practice over and over to form the muscle memory and use them on call when I need to. Or a shortcut to communicate what notes to play, without taking time to think and enumerate all of them.

But all in all, music is a free spirit, and all these concepts are simply effective vehicles to learn the paradigms, and communicate with others. This is why, for example, we're limited to the 15 key signatures and the ordering and positions on a stave are always the same, because we don't want to spell them out every time when reading a new sheet. And say you have a piece of music in C Lydian, you're absolutely free to use no sharps or flats on the paper - just accidentals on F# notes - or use a globally one-sharp key signature. Free speech Oh and there's definitely no need to restrict to the same set of notes as in a major scale. Blues, for example

jancivil
KVRAF
23649 posts since 20 Oct, 2007 from gonesville
conventionally there are 12 key signatures, for 24 keys.
However, sometime in the 20th c., other things happened.

It is equally true that the notes are the same for these three, and for another 4 modes of that set. However it is not true that "this is C harmonic minor", which has C as its *tonic*, the other six modes have their very own central tone; for lack of a word, their own tonic.

D (or any) Dorian is like basic minor with a raised 6th. What it is not, is C major starting on the note D. D is 'tonic' or it isn't a mode on D of any kind. A passage starting on D may or may not feature it as the central note. C major, or Ionian has its identity, 6 other modes of this set have their own.

Transposition changes nothing whatsoever. It's like the same pattern printed in 12 different colors.
Minor mode (vs major mode; a confusion may arise here, these are terms from tonal music, which is not modal music, the general meaning of mode rather than the specific) will have a minor third. A minor key will have that, and it will default to a minor 6 and 7, cf., key of A minor vis C major key.
And, the modes proper are typically ascribed minor or major categories. IE, Locrian, Phrygian, Aeolian, Dorian have this 'minor' property, while Lydian, Ionian, and Mixolydian have the property of a major 3rd.

mattrix3
KVRer

Topic Starter

22 posts since 1 Dec, 2021
Thank you,
It seems I am confusing key-signatures and keys. A key depends on the 'pattern' it is derived from.
As in the example a key-signature of C D E F# G A B may be either major or minor.
Would an experienced musician play a song differently depending on how they interpret the key signature?
What are the features of a song that determine its 'home' feel and 'resolution'?

How many of these 'patterns' have been named?
I have been flip-flopping around wikipaedia (for hours) and it seems to be a lot of them. Is there a list somewhere?

jancivil
KVRAF
23649 posts since 20 Oct, 2007 from gonesville
"key-signature of C D E F# G A B may be either major or minor."
the key signature is one sharp, F#. It may be used for anything that largely agrees with that set.
It's a key signature for two keys, G major and E minor. the other things, modes, aren't given the name key, one supposes it produces ambiguity and confusion, 'which' is 'the key'.

there's no interpreting a key signature, the music is or it isn't in the given key.

I have no idea, I don't find names of the things real interesting, and the synthetic scales acquire numerous names, and a lot of them describe a harmony as the idea for that particular scale, "Dominant Lydian" so-called has a #4 and a b7, I'm good with '4th mode of melodic minor'.

shawshawraw
KVRist
338 posts since 4 Aug, 2020 from Montreal, Canada
mattrix3 wrote:
Fri Dec 03, 2021 9:33 pm
What are the features of a song that determine its 'home' feel and 'resolution'?
In many cases it's the last melody note and/or bass note of a complete song. But beware, exceptions are everywhere and this can be style-dependent. Also the 'home' can change along the development of a song (what we call "modulation").
mattrix3 wrote:
Fri Dec 03, 2021 9:33 pm
Would an experienced musician play a song differently depending on how they interpret the key signature?
Not really. Maybe at most occasionally some subtle tweaks of the flow of a song when performing it. Key signature is a marginal factor.

jancivil
KVRAF
23649 posts since 20 Oct, 2007 from gonesville
gonna say it again: what key is not a matter of interpretation; sometimes the key signature does not suss what's happened for a couple reasons.
One is we have modulated keys but not yet signed the new key. It might not be signed if it's not of substantial enough duration. The key is or is not entirely sussed by the key signature. If someone sees one sharp and has a mistaken belief the music is G major when it is in E minor, they're simply in error; if there's some ambiguity their assessment of it is supposed to change what about the result? Hard no, the experienced musician is not going to do things with the music out of a mistaken impression from a sheet music.

The Satie I bring up has key signature of F minor; the tonic is F, it's a modal piece; but the first section has no Bb, its B natural is on the beat (on the harmony F, not an appoggiatura needing to resolve as such) and the main feel of the thing derives from that kind of exotic choice. The B section goes to IV (F Aeolian now) then it does F melodic minor ascending for the C section. Modally. The only Db is the 3rd of the IV harmony. This is not interpretation, I can see the notes on the page that aren't in the signature, I can hear them and play it by ear for that matter.
So Satie is the kind of guy that might write a key signature with a B natural, an E flat, and an Ab (this one has no bar lines).
1st bit Gnoss 1.jpg
But in 1890 he didn't.

It's somewhat rare to defy convention to that extent, but it is done.
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shawshawraw
KVRist
338 posts since 4 Aug, 2020 from Montreal, Canada
Agreed, thanks for closing the door, Jan!

mattrix3
KVRer

Topic Starter

22 posts since 1 Dec, 2021
Thank you people,
They tell us how important bars are, as they tell us what notes to emphasize. I wondered if something similar happened depending on whether the key was major or minor.

Much appreciated, but I got a little lost on some of the discussion.
My original questions were way more basic. I'm still counting semitones.
What is possible?, What is used?, What can be used & what can't? And why?
What the terms are, and are they specific or general, how are they used.

I have learned that the term 'key' is specific to either the major pattern or the minor pattern.

Does a signature have to relate to a key?
Is a signature with a single sharp on G allowed, despite not indicating a key?
What do we call the set of notes indicated by this or any other signature, if we don't call them a key?

Is the term 'mode' specific to a major key (aeolian, dorian etc)?
Does the set of notes with a single sharp on G have modes?

Is there something special about modes or are they just another 'scale form', like any other?
Last edited by mattrix3 on Sat Dec 25, 2021 7:16 pm, edited 2 times in total.

jancivil
KVRAF
23649 posts since 20 Oct, 2007 from gonesville
"Is a signature with a single sharp on F allowed, despite not indicating a key?"
Sure. If you want to signal the basic diatonic set of say C Lydian, there you are. There are seven different identities as modes one sharp may signal; two of seven modes are also said to be keys. The difference between those modes and, here G major and E minor as keys, is down to what you do with them. A key means internal functionalities prevail, chief of which is the dominant-tonic paradigm. If you have G A B C D E F# but "D7" does not function as dominant to G, it should probably be considered Ionian.

Mode isn't a key. For "C Lydian mode", et al, to be an identity C is its central tone. IE: the identities <C Lydian> and <G major are mutually exclusive>.

as to 'what is allowed', look, if you at some point figure your bit of music is pretty much going to have its B as flat, and its F as sharp, someone telling you the signature of B flat and F# 'simply can't be' is being dogmatic, stick-in-the-mud and you may feel free to ignore it. It's just some conventions.
Last edited by jancivil on Fri Jan 07, 2022 7:14 pm, edited 2 times in total.

mattrix3
KVRer

Topic Starter

22 posts since 1 Dec, 2021
You lost me.
F to G#, is 3 semitones.
I don't think the set is diatonic, but I'm not sure what diatonic is, there are multiple definitions.
It is certainly not rotationally related the major pattern,
Last edited by mattrix3 on Tue Dec 07, 2021 4:14 pm, edited 1 time in total.

jancivil
KVRAF
23649 posts since 20 Oct, 2007 from gonesville
there are not multiple definitions of diatonic. You may be seeing multiple definitions on the internet, there's a lot of crap out there.

A B C D E F G#, A harmonic minor, is diatonic. Period.
"F to G#, is 3 semitones." Your point is?

It's an augmented second. A B C D E F G, but that last one is raised a semitone. Diatonic. If you got, eg., a D# in addition to the D natural, this is a chromaticism. But A B C D# E F G is not chromaticism, either. Maybe we call it 4th mode of E harmonic minor.
Last edited by jancivil on Sun Dec 05, 2021 7:26 pm, edited 1 time in total.

mattrix3
KVRer

Topic Starter

22 posts since 1 Dec, 2021
I told you my questions were basic.
What is your definition of diatonic?

I have seen,
Made up of 2 disjoint tetra-chords
Containing only 2 semitone steps and 5 whole steps
" but the semitones are maximally separated.

The major pattern does all of these, the set with only a sharp on G does not.