Diatonic Notes in a Key

Theory
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I’ve been working on a lot of covers over the past year, and that’s been a lot of fun and I intend to continue with it.

That said, had my first “jam” with a buddy recently, and it highlighted the fact that in order to reach my musical goals, I need to be able to apply theoretical knowledge and to know what to play when I’m not simply playing something that’s already been written. This is exciting new ground!

For the next time we get together, we decided to take a more or less random jam track and work on it. So I started putting together a cheatsheet to focus myself, and I have a couple of questions.

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First of all, it was cool to see how the notes of the pentatonic scale “work” for all the scales in the key. I kinda knew that, but it was cool to see it hold true when worked out on paper.

So anyway, the notes above are specific to the progression, so I don’t have the IV or the vii scales enumerated, as they aren’t used.

I noticed, though, that if I took the major/minor scales respectively for all the notes in the scale of G major, I end up with a few notes in those scales that are non-diatonic, which are highlighted in yellow.

Is this right, or am I looking at this wrong?

Next question, assuming this is right, should I avoid those notes? Granted, if I stick with roots and 5ths to start, even working in the respective major/minor thirds, I’ll not even run into these notes, which are 2nd, 6th, and 7th scale degrees respectively.

But in general, theoretically, is this the correct way of looking at it? I guess I was expecting all the notes of the scales would be diatonic and it surprised me to see otherwise. (Unless of course I did something wrong, still working to get my head around it.)

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If you want to be strictly diatonic, the I chord is a major 7 chord (not a dominant 7 chord as you have it here). The dominant chord is the V chord in a diatonic chord progression.

So, in G major, the I chord is Gmaj7, which has a major 7th (i.e., the F#). The ii chord is A min7, which has a natural 6 (in the scale),i.e., the F# (NB: this is the dorian scale).
The iii chord is a minor chord (B min7) which has a flat 2 in the scale (the C); this is the phrygian scale.
The IV chord is a major chord (C maj7), but has a #4 (here the F#) in the scale (lydian)
The V chord is the dominant chord (D7), which has a minor 7th (C); mixolydian scale
The vi chord is E min7, which is the natural minor (aka, aeolian scale).
And the vii chord is funky, because it’s a half-dimished 7th chord (F# min7b5).

:smile:

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I don’t know, but that is exactly the way I look at it in the phase of bass playing where I’m now, so there must be something good there :smiley:

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Yes, I wrote that down incorrectly. Here’s the actual progression:

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After work today I’ll try to digest your response, @joergkutter , thank you!

I guess my question is a bit more general. Putting aside this specific progression, say these were all just straight major/minor chords in the key of G major.

As an example, the ii chord is A minor, right? So when playing in the key of G and it goes to the ii chord, are all of the notes in the A minor scale usable? Even the 6th (F), which is non-diatonic? Or should it be avoided?

Same for the iii chord, B minor, where the 2nd degree of B minor (C#) is non-diatonic.

And same for the IV chord, D major, where the 7th degree (C#) is non-diatonic.

As I said, I’ll go back and study what you’ve provided for that progression (again, thanks!), but first I think I need to understand this more fundamental question.

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So, purely from a theory point of view (because in the real world, you can do whatever you want, as long as it pleases your ear and those of your fellow musicians), “diatonic” means that all the chords and scales use ONLY the notes from the parent major scale, i.e., here from G major. And thus: NO F, NO C#, etc.!

So, while you have correctly identified A min7 as the ii chord (in a song that is diatonic in G major), were you go wrong is in assuming you could use the natural minor scale to play over that ii chord.

You see, there are several flavors of minor; not just the natural minor, which you probably know best (aka the relative minor. That is E minor for G major).

The question that you really want answered is: I recognize A min7 as the ii chord in a progression diatonic in G major, now which are the notes I can play safely over this chord? The answer is: all the notes of the A dorian scale.
Similarly: I recognize D7 as the V chord in a progression diatonic in G major, which are the notes I can safely play over this chord? Answer: all the notes of the D mixolydian scale.

And so on:

Degree - Chord name - scale notes - scale name

I - G maj7 - G, A, B, C, D, E, F#, G - G ionian
ii - A min7 - A, B, C, D, E, F#, G, A - A dorian
iii - B min7 - B, C, D, E, F#, G, A, B - B phrygian
IV - C maj7 - C, D, E, F#, G, A, B, C - C lydian
V - D7 - D, E, F#, G, A, B, C, D - D mixolydian
vi - E min7 - E, F#, G, A, B, C, D, E - E aeolian (E natural minor)
vii - F# min7b5 - F#, G, A, B, C, D, E, F# - F# locrian

(Note: all the notes that show up in these scales are the exact notes of the G major scale!!)

Hope this helps a bit more!?!

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The trick here is that we have limited vocabulary to talk about this stuff!

So - if the chords were all straight major or minor and everyone agreed that the key of the jam was G major, here’s how the information would break down.

The chord information - for simple major or minor chords (also called triads, because they’re 3 notes) - would only have the notes of the chords.
Forget about scales.
Attaching a scale to a chord is a very imperfect and approximate and subjective science.

So if you look at chords and chords only (and simplified it all to triads), you’d get:

G maj = G,B,D
A min = A,C,E
B min = B,D,F#
E min = E,G,B
A min (again)
D maj = D, F#, A
G maj (again)
A min (again)
D maj (again)

If you start the jam and focus only on the notes of the chords and no other notes, you’ll have an excellent and solid way to play on this progression.

If you take the first step and want to have more scale stuff to play, you can play a major or minor pentatonic depending on the type of chord.
All major chords get major pentatonic as the scale to play with.
All minor chords get minor pentatonic as the scale to play with.

What @joergkutter is talking about is the next step, where you have a 7 note scale to play with from each of the given chords, and all the notes stay in the key of G.

That step is a good theoretical step, and it will be helpful…

But it is challenging, and it involves tiny changes between the different patterns (modes) and, I find, it’s much less practical in a jam setting then just playing pentatonics.

To more specifically answer the question that you had:
Not all major and minor scales are the same. There are many variations of each.
So you will run into problems if you play a natural major scale or natural minor scale (the 7 note scales) when you see a major or minor chord.

You’re extrapolating a 7 note pattern from only 3 given notes, and there’s a big margin of error for what other 4 notes you choose.

The nice thing about pentatonic scales is that they eliminate the dangerous notes for you. You’re only adding 2 more notes to the 3 you had from the chord, and the notes you add will always sound good.

To add a full 7 note scale based off of just a chord, it’s back to the world of keys, modes, chord-to-chord relationships, and there are more nuances and details involved that - in my experience - don’t help much when grooving bass lines in a funk/pop/rock jam.

Lemme know if this helps at all!

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YES!

@fennario : @Gio has got you covered for the real world; his advice is directly usable hands-on knowledge!
I was talking from the celestial plane of pure theory… a place you can visit at your leisure whenever you feel curious :wink:

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@joergkutter and @Gio - THANK YOU, this is immensely helpful! Your replies will be of use as I start down this path, as well as further down it when I’m ready to dive into modes and shore up my very limited understanding.

I think my naive question could have been a bit more focused, as the immediate thing I was looking for is “WHAT is the palette of notes I have to work with for each chord of the progression”. The theory question goes hand in hand with it, so I can understand WHY that’s the case. By completely grokking the WHY, the WHAT will hopefully make more intuitive sense. I totally want to understand how modes work, but… later. For now, you guys have armed me to the teeth with exactly what I need.

Again THANK YOU BOTH!

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If you want a great tool to explore music theory and chord progressions, check out Scaler 2 (3 is coming out soon). It lets you play with all those things. If you start working on composition and using chords and progressions, you’ll understand them much better.

I also found it helpful to work on jazz/improvisation as a 2/5/1 is an easy progression to follow and understand. When you do that you’ll also get an understanding of how chords and modes fit together eg the V chord of a scale and the mixolydian mode.

The simple explanation of the chords in a key and the modes of a scale are that the key is your palette and you mostly choose from those notes and that’s why you end up with maj, min, min, maj, dom, min, dim because they all use the notes from the key.

if you play a progression of the major 7, dominant 7, minor 7, half diminished 7 (aka min 7 b5) versions of a chord you just have to flat one note from the previous chord:

major 7
dominant 7 (major 7 with a flat 7)
minor 7 (dominant 7 with a flat 3)
half diminished 7 (minor 7 with flat 5)

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Here’s a good video on modes for… later :slight_smile:

if you have trouble remembering the modes, i use the mnemonic:

I (Ionian)
Don’t (Dorian)
Particularly (Phrygian)
Like (Lydian)
Modes (Mixolydian)
A (Aolian)
Lot (Locrian)

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