Major or Minor?

[Silly Moustache]

Originally Posted by Mr. Jelly

When a song uses major and minor chords what makes either a major or a minor key?

I've kept out of this to see how others respond.

The trouble with understanding chord progressions and such is that there is usually Too Much Information.
To answer this question simplistically :

What we are talking about is called "chord progressions" in songs.

Songs can have only one chord (boring) 2 chords , simple, three chords (very very common in blues, country folk) and 4 , 5 or six chords (more chords more melodic)
You can even have seven chord progressions but that involves the 7th chord (a "half diminished" which is the red haired stepchild of the family (apols to any redheads here)

You If you start a piece/song whatever with a Major Chord, then you will also have the "option" to use minor chords as well.

Say start with a C chord - then most songs will be in C (I), F (IV) and G (V) with that you canplay almost every blues, country etc.

To give it more melody as can add a 6 (vi) chord which would be an A minor , or an Eminor (ii) or even a Dm (ii)

This is because every note in the scale can also be the root of the chords that will with the root/key of C :

C, D,E,F,G,A,B,and C (or) I, ii, iii, IV, V, vi, and vii (dim)

I'll stop there before this simplified explanation becomes too complicated.

It would be nice if you responded to tell us if you found any of this helpful, and whose answer helped most, if any. d

[Robin, Wales]

Originally Posted by JonPR

Right! Because DADGAD is a close cousin to "mountain minor" banjo tuning: GDGCD. That's DADGAD at 5th fret (less the 1st string).

Mountain "minor" is of course too precise as a name, but the whole point is that - as a variation of GDGBD - it enables playing in G minor as well as G major. Not to mention mixolydian...

It is weird that you should mention mountain minor. I was messing around on banjo about 8 years ago and came up with a tuning that allowed me to easily play Aeolian, mixolidian and Ionian from one open position. I just stole AEae from cross-tuned fiddle and went for it on banjo. There are no "chords" just melody across drones messing with your head and saying "that's major" "nope, now that's minor" I haven't picked up a banjo for 5+ years but did record myself playing this A'AEae tuning. I'm certain that this is a "known" banjo tuning but haven't looked it up.

[Mr. Jelly]

Originally Posted by stanron

The scale the melody uses..

Maybe I missed it, but this seems to be the closest to an answer. And of course, the melody and in turn the scale of the melody may change as a song progresses. Thanks for a good discussion. Allot of good stuff.

[mr. beaumont]

Originally Posted by Robin, Wales

It is weird that you should mention mountain minor. I was messing around on banjo about 8 years ago and came up with a tuning that allowed me to easily play Aeolian, mixolidian and Ionian from one open position. I just stole AEae from cross-tuned fiddle and went for it on banjo. There are no "chords" just melody across drones messing with your head and saying "that's major" "nope, now that's minor" I haven't picked up a banjo for 5+ years but did record myself playing this A'AEae tuning. I'm certain that this is a "known" banjo tuning but haven't looked it up.

DADGAD is a very interesting and versatile tuning, because it's not major or minor. As is your AAEae tuning (though that one doesn't quite have the chordal possibilities of DADGAD)

Back to the OP, yes, the scale that the melody is in is a good tip off. Though some songs use surprisingly simple melodies that you might not be able to pin to one scale...

[Robin, Wales]

Originally Posted by mr. beaumont

DADGAD is a very interesting and versatile tuning, because it's not major or minor. As is your AAEae tuning (though that one doesn't quite have the chordal possibilities of DADGAD)

Back to the OP, yes, the scale that the melody is in is a good tip off. Though some songs use surprisingly simple melodies that you might not be able to pin to one scale...

Hi Jeff, just realised that my soundcloud track wasn't working. You may be able to hear the major v minor ambiguity now that I have amended my post. It shows what you are saying. The melody sets the mode.

[Bluenose]

I can think of a couple of Norman Blake tunes that have intros with heavy use of the E minor chord but then go to Gmaj, Dmaj and Cmaj which are chords in the key of Gmaj. E is the 6th of G and also the relative minor of Gmaj. My point is it's not always the first chord you hear in a song that determines the key. Relative minor chords are often used as substitutes for the tonic major chord.

[JonPR]

[delete]....

[JonPR]

Originally Posted by Mr. Jelly

Maybe I missed it, but this seems to be the closest to an answer. And of course, the melody and in turn the scale of the melody may change as a song progresses.

Exactly.

There is a "scale", which is formed of the notes used by the melody and the chords. Sometimes this is just 7 different notes, which we can easily identify (theoretically) and notate as a "key signature". Other times - very often - there will be extra notes in there (chromatics, blue notes, notated as "accidentals).

The "key" is the sense of overall "tonal centre" or "home": the feeling that there is one primary chord where the progression feels most stable, like the period on a sentence. That's the chord that the song will almost always end on - unless the composer (or musicians) want it to sound unfinished at the end, which they sometimes do!

Most of the time, in popular music of most kinds (except jazz), that will also be the first chord. And if the first and last chord are the same, then that's 99% certain to be the key. (Jazz standards often start on a non-key chord.)

However:

(a) In order to play the song perfectly - including improvising on it - you don't have to know what the key is (i.e, be able to hear and identify the tonal centre). You just have to know how to play all the chords. And ideally (if improvising) the melody too. In some songs, the tonal centre is actually ambiguous - it's hard to be sure which chord is "home". It doesn't matter!

(b) identifying the key (if you can) doesn't restrict the song to the scale implied. E.g. you might hear G major as the obvious key chord - first and last, and the chord that "sounds like home" elsewhere in the song. But the song could easily contain (as well as C and D) major chords like F, A, B, E, Bb or Eb, and maybe Cm. All those are pretty common "chromatic" chords in the key of G major. No rules are being broken!

In short, issues of theory (what key is it? what chords "belong"?) are peripheral. It's good to be curious, but it's not essential knowledge at all.

Fable: there was once a centipede who was told it had 100 legs; then found it could no longer walk. I.e., you can overthink these things!

[sprucetophere]

This is good stuff... it took me far too long to understand what is useful to me (and I would think most people). And IMHO this sums it up well.

Originally Posted by JonPR

Exactly.

There is a "scale", which is formed of the notes used by the melody and the chords. Sometimes this is just 7 different notes, which we can easily identify (theoretically) and notate as a "key signature". Other times - very often - there will be extra notes in there (chromatics, blue notes, notated as "accidentals).

The "key" is the sense of overall "tonal centre" or "home": the feeling that there is one primary chord where the progression feels most stable, like the period on a sentence. That's the chord that the song will almost always end on - unless the composer (or musicians) want it to sound unfinished at the end, which they sometimes do!

Most of the time, in popular music of most kinds (except jazz), that will also be the first chord. And if the first and last chord are the same, then that's 99% certain to be the key. (Jazz standards often start on a non-key chord.)

However:

(a) In order to play the song perfectly - including improvising on it - you don't have to know what the key is (i.e, be able to hear and identify the tonal centre). You just have to know how to play all the chords. And ideally (if improvising) the melody too. In some songs, the tonal centre is actually ambiguous - it's hard to be sure which chord is "home". It doesn't matter!

(b) identifying the key (if you can) doesn't restrict the song to the scale implied. E.g. you might hear G major as the obvious key chord - first and last, and the chord that "sounds like home" elsewhere in the song. But the song could easily contain (as well as C and D) major chords like F, A, B, E, Bb or Eb, and maybe Cm. All those are pretty common "chromatic" chords in the key of G major. No rules are being broken!

In short, issues of theory (what key is it? what chords "belong"?) are peripheral. It's good to be curious, but it's not essential knowledge at all.

Fable: there was once a centipede who was told it had 100 legs; then found it could no longer walk. I.e., you can overthink these things!

[Horseflesh]

Originally Posted by mr. beaumont

Let's take the C major scale, for example:

CDEFGAB

If we stack those notes in the intervals of thirds, we get chords. That sounds confusing, but it's not...it's simply taking every other note.

So...

CEG is C major ...

So by just stacking thirds in the major or minor scales we get the chords in that key, with majors and minors falling where they should, like for major: I, ii, iii, IV, IV, vi, vii*.

How did I never see that before? Neat. That's going to be good for my bass playing where you are always picking out chord tones ... An excellent reason to study the scales.

[rick-slo]

Originally Posted by Horseflesh

So by just stacking thirds in the major or minor scales we get the chords in that key, with majors and minors falling where they should, like for major: I, ii, iii, IV, IV, vi, vii*.

How did I never see that before? Neat. That's going to be good for my bass playing where you are always picking out chord tones ... An excellent reason to study the scales.

Hear the intervals (such as where the full steps and half steps are in a particular scale, such as major third and minor third chord intervals).

[JonPR]

Originally Posted by Horseflesh

So by just stacking thirds in the major or minor scales we get the chords in that key, with majors and minors falling where they should, like for major: I, ii, iii, IV, IV, vi, vii*.

Exactly. Here's a chart demonstrating it:

 Half-steps: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
Major scale: C     D     E  F     G     A     B  C     D     E  F 
CHORDS:
  I = C      C  .  .  .  E  .  .  G
 ii = Dm           D  .  .  F  .  .  .  A
iii = Em                 E  .  .  G  .  .  .  B
 IV = F                     F  .  .  .  A  .  .  C
  V = G                           G  .  .  .  B  .  .  D
 vi = Am                                A  .  .  C  .  .  .  E
vii = Bdim                                    B  .  .  D  .  .  F

The chord names derive from their most significant intervals - i.e., chord structure and naming is more about intervals than scales.

The first six chords all have "perfect 5ths" (7 half-steps from the root). So it's the size of their 3rds that differentiates them. 4-half-steps = larger = "major". 3 half-steps = smaller = "minor". (That's all "major" and "minor" mean.)
In chord symbols, the major 3rd is treated as default, so "C" alone means a C major chord (taking M3 and P5 for granted). We add "m" to indicate a smaller (lower) 3rd.

The last chord has a "diminished 5th" - half-step smaller than "perfect" - which is a highly distinctive interval (more than its minor 3rd), hence the name for that chord.

Adding 7ths works the same way - the next alternate scale step - and produces other chord types, also named according to their intervals, but in a slightly different way.
The 7th intervals come in two sizes, major (11 half-steps) and minor (10 half-steps). There are five of the latter and only two of the former, so the minor 7ths are labelled just "7", while the bigger ones are "maj7".
This is handy for the shorthand, because default is the opposite from the 3rds - meaning the most common combination of intervals gets the shortest chord name:

"G7" = G, major 3rd (B), perfect 5th (D), minor 7th (F). All the defaults. (It gets called a "dominant 7th" chord, because it's the 7th chord build on the "dominant" (V) degree of the scale. That's the only scale degree that produces that set of intervals.)

If we lower the 3rd and raise the 7th, we get "Gm(maj7)" = G Bb D F#. Pretty rare, so the long clumsy name is not an issue. (Notice we don't need to know the scale: the chord name is a result of its intervals, related to a shorthand interval naming system.)

Adding 7ths to the diminished triad involves an adjustment to the shorthand. So, you might think if we add the standard minor 7th to Bdim (B D F A), we'd get "Bdim7". But we don't. "Bdim7" is B D F Ab, and comes from C harmonic minor. In this case, "dim7" refers to the B-Ab interval, which is a half-step smaller than a minor 7th, meaning a "diminished" 7th.
So B D F A needs to be called "B half-diminished" (because it only has one diminished interval, B-F), or "Bm7b5", as if it's derived from Bm7 (B D F# A) with its 5th lowered.

Again, this is all independent of scales. Scales themselves are named after their most significant intervals. "Major" and "minor" scales - like chords - are named after their 3rds. The "major scale" happens to have other major and perfect intervals, but "minor scales" have a major 2nd, and can sometimes have major 6th and major 7th too. In the "melodic minor" scale, the only minor interval is the 3rd.

[Horseflesh]

JonPR, thanks a million, what a great post. This cleared some things up for me. The infographic is great! I'll be reading this a few times for sure.

[JonPR]

Here's another infographic you might find handy: all the common intervals in one octave:

      Half-steps: | | | | | | | | | | | | |
 Interval number: 1 <2> <3> 4   5 <6> <7> 8
Interval quality: P m M m M P   P m M m M P

Neat. right? The missing step is the famous "tritone": 6 half-steps, which is either an "augmented 4th" (if the P4 is raised) or a "diminished 5th" (if the P5 is lowered).

In almost all the scales in common use, the P(erfect) intervals are fixed, while the others can be in various "modal" permutations. I.e., the 2nd, 3rd, 6th and 7th can all be in either the minor or major position, although of course some combinations are more common than others - mainly because of what chords they produce.

It gets more complicated because there are such things as "enharmonic" intervals - like the tritone - which sound the same but have different names depending on context.

When I mentioned Bdim7 being B D F Ab - and B-Ab being the "diminished 7th" interval it's named after, you might wonder why it's not spelled B D F G#. B-G# is a major 6th, so can we call that chord "Bm6b5"?
Well, in theory we could. But B D F G# comes from A harmonic minor, and is actually an inverted G#dim7, because that's how the 1-3-5-7 stack works: G# B D F in alternate steps, G#-F being the definitive "diminished 7th" interval.

In practice, getting the right enharmonic spelling for a chord doesn't always matter (it sounds the same, so who cares? ), but it can help when trying to make sense of the theory. The key of C minor has an Ab, because it already has a G. The key of A minor has a G#, because it already has an A.

[Horseflesh]

Oh that's a good one too!

I may work from these and make my own colorized versions, it helps me remember things.