Shared chords between keys

[Taika-Kim]

I started doing a table to help myself plan changes of key, etc, since I'm not that good with any very advanced work with key changes, harmony progressions with them, etc.

So for example for C minor the number of shared chords with other major/minor keys are:
In scales of:

Dm- 2: Gm, A#
D# - 7, all of them
F- 2: Gm, A#
Fm- 4: Fm, G#, Cm, D#
G#- 4: G#, Cm, D#, Fm
A#- 3: A#, Cm, Gm

And that's all of them.
So number of times degrees are shared goes:
I - 3
II- 0
III - 2
IV - 2
V - 3
VI - 2
VII - 3

Did I got this correct? So there are no keys where Cm shares only one chord? Or did I miss one? And none of the degrees is shared only once with another basic minor or major scale?

[jancivil]

If you're going to work with keys and definitions you first need to lose this basic mistake in spelling.
D minor as a key is signed with a Bb (same key signature as F major). A# is a different function in tonal music, and it's a reach in terms of key, for starters. It only first appears in a key signature at B major, #5 of 5 sharps. Six places distant in the circle of fifths.

A# major as a triad is A# Cx E#.

So you'll actually save yourself this whole task with a basic look at the circle of fifths and key signature. The answers are obvious, there is no need for all this.

IE: C minor and D minor are flat keys; one has three flats, the other one flat. Keys F and D minor have the same key sig.
Chords are built in thirds. This will all be available in some basic charts.
(There are chords belonging to D minor which to exist in a passage in F major will be borrowed from it but that exceeds the lesson for today.)

Google is your friend here. You seem to be trying to sort this from the piano roll purely (where there are only sharps in the graphics) and your own suppositions. Not the best use of your time, tbh.

[fmr]

So you'll actually save yourself this whole task with a basic look at the circle of fifths and key signature. The answers are obvious, there is no need for all this.

^^^ THIS ^^^

Forget all that rubbish about shared chords. All you need is a comprehension of the tonal functions in each tonality.

Let's say you want to go from C minor to D minor. If you have the Cm chord, all you have to do is go from there to the tonal chords of D minor (which are Dm, Gm and A Maj). So, you can go from Cm to Gm, and from there to A Maj. And "voilà" - you are already in D minor.

[jancivil]

Right, I was about to say that, 'shared chords' is barking up the wrong tree. That's coincidence, music is context and harmony in keys is about function.

[Taika-Kim]

But let's say I am in D minor, and from there I might want to go to a number of different keys. Unless I have memorized them, I don't have an easy way of considering relatedneds. The circle of fifths shows it, but it does not reveal the scale degrees that are shared between keys and their relations, or does it?
Because if I introduce too many new notes at once, the chord change might be hard to listen to? Because I really don't remember every chord of every key outright from memory. So let's say that I'm at an Am chord currently, and I want that to be part of a certain cadence, let's say II-V-IV-V-I, and I want to go next to that V diatonically, and also make sure that in that final I I'm not straying more than, say, one note from the original key. The c5ths shows obviously close keys, but not how related those IV and V chords are to my original key. Or does it?

O come from a background in electronic not very harmonically rich music, so yes I'm looking at this through sharps only. But a note is a note, what does it matter if I call a note d sharp or e flat?

But thanks! Until now I've been kind of just doing what sounds good, but I'm intetrested in learning a more systematic approach to help edit compositions etc. It might very well be that I"m really not looking where I should be...

[fmr]

But let's say I am in D minor, and from there I might want to go to a number of different keys. Unless I have memorized them, I don't have an easy way of considering relatedness. The circle of fifths shows it, but it does not reveal the scale degrees that are shared between keys and their relations, or does it?
Because if I introduce too many new notes at once, the chord change might be hard to listen to? Because I really don't remember every chord of every key outright from memory. So let's say that I'm at an Am chord currently, and I want that to be part of a certain cadence, let's say II-V-IV-V-I, and I want to go next to that V diatonically, and also make sure that in that final I I'm not straying more than, say, one note from the original key. The c5ths shows obviously close keys, but not how related those IV and V chords are to my original key. Or does it?

It's hard to try to explain to you these things, because the imply solid knowledge of the principles of tonal harmony, and what are the functions. In your quoted chord progression "II-V-IV-V-I", the second degree is used in place (as a replacement) of the fourth degree. This sounds to many as a stronger chord progression because the root of the II has a relation of fifth to the root of the V, which also has a relation of fifth to the root of the I. This is one of the things the circle of fifths tells you. Try to play the roots of those three chords (II - V -I). For example, if you are in D minor, what you have is E, A, D. Now keep going - (E, A, D, G, C, F, Bb, Eb, Ab, Db(C#), F#, B... etc. You could go on with this "ad infinitum".

This is a way to modulate from any tonality to any tonality without "forcing" anything. That's the way Beethoven did the modulations (more or less - there were more things about it). Later, we could observe some things like chromatic progressions, where you would pick a certain note of the chord, raised it or lowered it, and would transform that chord into something else, that would allow you to progress quickly into some distant tonality. This is even easier in minor keys because their diminished seventh (the chord built over the raised seventh degree of the tonality) is a symmetrical chord, therefore you could resolve it into the home tonality or into a foreign tonality, by simply interpreting it enharmonically (calling the chord notes other names). Which leads us to...

I come from a background in electronic not very harmonically rich music, so yes I'm looking at this through sharps only. But a note is a note, what does it matter if I call a noted sharp or e flat?

You can't. A chord is built ion a certain way. The main chords, those that are built over the tonal degrees, and carry the harmonic functions of the tonality, have to be spelled correctly for them to even make sense. Any musician, when it seels an A#, expects that A# to progress to B, because that's a natural movement., But if you have a Bb, it is expected to move to A, or maybe C, but never B (because a key that has Bb doesn't have B, and vice-versa), unless you are using chromaticism, and modulating to a distant tonality. You said: "note is a note". NO, IT ISN'T. The sooner you stop thinking like this, the better. A sound may be a sound, and two notes may sound the same (if you are using twelve-tone equal temperament, which is what most of us use), but they are still two different notes. An A# is NOT a Bb, because the first belongs to a certain key, and the other belongs to another, completely different, key. They may sound the same, but they are NOT the same. And to build a chord, you have to use the proper notes, and spell them correctly (otherwise, things will not make any sense - it would be like mixing words in different languages).

It seems you lack some basic notions about music theory and about basic harmony. You better start by studying those subjects before move on. Study how tonality is built, study what is the circle of fifths, study basic harmony (chord building, tonal functions, cadences), and then you may proceed to what you are trying to do now.

BTW: The relatedness is given to you by the circle of fifths. Each tonality has five other tonalities which are "related" (close) to it, being them, the relative (the Major tonality for the minor and vice-versa), and the ones (Major and minor) that differ to it in the key signature by just one accident.

Therefore, D minor is related to F Major (its relative Major), and also to C Major and A minor, and Bb Major and G minor. That's what you can see easily in the circle fo fifhts. Now, to interchange between these, you have to know what are the tonal functions of each of these tonalities. They are always the I, V, and IV(II). Beware that for the fifth to be a tonal function in minor mode it must have the major third (the leading tone). Therefore, the chord of A min is NOT a tonal function of D minor. A Maj chord is. If you use A min you will not have the leading tone, therefore, no attraction to the I. If you interchange D min and A min chords often, it will give you a different feeling, a kind of modal flavor, but is weak in terms ot tonal harmony. You CAN do it, but it will not give you the feeling of tonality.

[Taika-Kim]

Thank you! That was a lot of clarification condensed. I've written a lot of diatonic modal music, so yes I'm probably missing a lot of the basics of moving between keys, or at least a solid understanding of it. But about writing notes... On a piano roll, notes only have sharps, so there is no way really to even use flat names. So I'm kind of forced to use them. I might try to think of something else than what I see but that gets confusing really.

Anyway, I will give a good thought to what you wrote there!

[trewq]

Thank you! That was a lot of clarification condensed. I've written a lot of diatonic modal music, so yes I'm probably missing a lot of the basics of moving between keys, or at least a solid understanding of it. But about writing notes... On a piano roll, notes only have sharps, so there is no way really to even use flat names. So I'm kind of forced to use them. I might try to think of something else than what I see but that gets confusing really.

Anyway, I will give a good thought to what you wrote there!

If you have a PC you could try:
www.chordwarepa.com

Just use the AND feature for shared chords of the scales you select.

You can also select between displaying sharps or flats.

[Taika-Kim]

Good tip, thanks! I like Harmony Assistant actually for exploring these things, but the UI and workflow was tortuous. If that's not a word, we need to decide it is for this situation.

[trewq]

I forgot to add that in CPA every chord and scale is a unique note group. For example, if you are looking for A natural minor, it will only show the C major.

Its part of the tradeoff between chords/scales which are hardcoded verses generated using theory.

[jancivil]

But let's say I am in D minor, and from there I might want to go to a number of different keys. Unless I have memorized them, I don't have an easy way of considering relatedneds. The circle of fifths shows it, but it does not reveal the scale degrees that are shared between keys and their relations, or does it?

The circle of fifths shows the variance in terms of distance. I can't emphasize this too much, the notions of 'shared' and now 'the scale degrees' are coincidences, they are like little factoids. There is no meaning in them per se.

Objectively, the distance between C major/A minor and F major/D minor is one flat. It's the least distance you may travel and still be a difference. C major to C# major is 0 sharps to 7 sharps. In terms of key relations it's at opposite ends, it's rather like blue to orange.

Because if I introduce too many new notes at once, the chord change might be hard to listen to? Because I really don't remember every chord of every key outright from memory.

The first question there is totally contextual. It might be, it might be exactly the effect. For instance this cover of Creep I dig, done by singer Haley Reinhart does the typical, hoary old modulation up a tone for the last bit. While I think it's corny af to do, it's done in such a way that really elevates the emotion and in this arrangement and how she works it is just exciting. Technically a tone up out of nowhere [abrupt modulation] is not the smoothest, and to a classical person might well be a bit gauche in itself. Is it 'hard to listen to' per se? It's done all the time. IE: it's all about context.
Just about as prevalent in pop music arranging is an instant modulation everything is suddenly up a semitone; as distant a modulation as possible. Same things to be said as w. up a whole tone, only perhaps more flagrant. People go for it nonetheless because of expectation of a context, tends to rule over the technicalities.

So for you the things which aren't the closest proximity are going to be 1) technically challenging, and 2) out of this, difficult intellectually and aesthetically. Because you have a conservative point of view right now.
SO: note well, objectively close vs distant. This is the reliable, true indicator of the amount of 'new notes' or as to that heretofore uncommon to initial key. You're sticking to your supposition of 'shared scale degrees', which is a bit of a red herring.

F to D minor is nothing. F to D major, the distance of the minor third isn't the issue, it's distance of tonalities or keys. The D major harmony in F major key may or may not be jarring just by the fact, it's a matter of handling. It's a secondary dominant, V of ii. Rather common, in fact. E major is V of iii. New notes, relations beyond merely the circle of fifths chart, yes. Upsetting per se? Contextually, not necessarily. Note the relationship of the 5th, anyway.

But a note is a note, what does it matter if I call a note d sharp or e flat?

I told you some things about that right off the bat. Pay attention. Note names have meanings particularly in tonal music.
A# is what it is. In serial dodecaphony (12 tone serial "atonal" music) Bb and A# are usually quite interchangeable, the meaning is not tied to a magnetic relationship to another [primarily to a central] tone. A# is meaningful to sharp keys; it is the 5th occurring sharp in the circle. It is the leading tone to the key of B major. It is the 3rd of its V, F# major, ie., its dominant.
Bb is the perfect 4th of key of F major. It has that close relationship with its government. NB: Keys F and B are six places in distance.
NB: G Bb D. Any G to any B note: G A B, 1 2 3, a third. Your basic building block for chords/harmony is this.
G A# is a second. The interval is used differently. Then you'd have A# to D, a diminished fourth. It isn't useful. You have a flat key you derived it from. A# is extraneous, there is no use. At least before we get seriously chromatic.

And then we get into <what use is there> for the interval:
B harmonic minor has this augmented second in it, 6 to 7, G A#. Typically G A# B. Harmonic minor, and particular ethnic musics make use of the_actual_interval. IE: scale-wise. B C# D E# F# G A# contains 2 aug 2nds. B harmonic minor is that except for the E# (w. an E natural). Note well alphabetical series. F major: F G A Bb C D E.
There's the reasoning for those note names. The differences are all to do with musical meaning.

But as I said, and literally every knowledgable person will have this exact advice for you, you have to deal in this language if you're going to even think about usage of keys. It is the fact. You're either going to proceed coherently or you aren't, you will have a mess on your hands if you don't.

You're going to continue to create useless and wasteful tasks if you won't. You get the basic lay of the land under your feet before you walk about not knowing where your feet will land next.

[jancivil]

But about writing notes... On a piano roll, notes only have sharps, so there is no way really to even use flat names. So I'm kind of forced to use them. I might try to think of something else than what I see but that gets confusing really.

You are not forced to rely only on a computer DAW to work this out! Actually it's best to get your thing together outside it (or at least in a notation application), as here the experience is specifically hampering you. MuseScore is freeware.

Anyway, funnily enough I caught this out the corner of my eye in Nuendo just now.

it knows from flats.png

I wasn't even trying to see that, but I have set certain preferences so the thing has a best guess. The tonic here is Bb, I'm thinking in Bb so the decisions go to Bb and there is the machine's idea of a harmony. Which is pretty much spot on.

[jancivil]

Also, knowing what chords belong to key is not a rote memorization task, it's knowledge-based. Seven note scale, seven objects constructed in the interval of a third, known as triads. With minor, conventionally, there are two more possibilities from scales.
You must internalize concepts.

Yes, it doesn't necessarily come overnight, but it's a grammar. To speak grammatically one has to grasp it conceptually, I don't picture sentence diagrams and doubt I ever did but I internalized usage.

[Hooj]

.... yes I'm looking at this through sharps only. But a note is a note, what does it matter if I call a note d sharp or e flat?

cuz this is a music forum!

Your, You're, Yore ....

all 'sound' the same but they are NOT the same are they???