What about songs that are not in the same key?
View the full lesson at Non Diatonic Chords | JustinGuitar
When maj7 chords appear in a chord progression, are there any clues to guessing what key the progression is in? Like do maj7 chords commonly replace certain scale degrees? For example, they only can be in I, IV, V? Or can they appear anywhere?
Are Maj7 chords simply the addition of the VII degree note into the regular Maj chord?
I was playing Rocksmith, practicing rhythm arrangements and on the song Hey Ya! by Outkast, the chord progression is G, C, D, E. If you were trying to figure out the key of a progression like that for a solo or something, what would you do with that?
It fits closest to the Key of G, but has an E maj instead of a E min. We would just call this a non diatonic chord progression and work with the key it fits closest into?
I suggest running through Richard’s wonderful thread on the old forum about borrowed chords. This one seems like a clear example where you borrow E maj from G minor scale long story short. How to improvise is itself a big topic as you are entering muddy waters of Modes 
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In any set of seven diatonic chords there are three major and three minor plus a diminished.
Of the three majors (I, IV and V respectively), when extended from a triad formula to a four-note form (JUstin calls these quadads) one and one only becomes a 7, the other two become major 7.
The I (root) and the IV both become major 7.
Only the V, the dominant, becomes a 7 and is, naturally called a dominant 7.
This is all due to the immutable and inevitable consequence of constructing such chords by stacking in thirds.
Take the key of E major.
I chord = E major
IV chord = A major
V chord = B major
E major scale (multiples of):
The I chord
1, 3, 5 = E, G#, B = E major
When extended
1, 3, 5, 7 = E, G#, B, D# = E major 7
The interval from E to D# is a major 7th (11 semitones - check the Note Circle).
The IV chord
4, 6, 8 = A, C#, E = A major
When extended
4, 6, 8, 10 = A, C#, E, G# = A major 7
The interval from A to G# is a major 7th (11 semitones - check the Note Circle).
When written as a chord formula in relation to its own root, it takes the form 1, 3, 5, 7 - just as the I chord does.
The V chord
5, 7, 9 = B. D#, F# = B major
When extended
5, 7, 9, 11 = B. D#, F#, A = B major 7
The interval from B to A is a minor 7th (10 semitones - check the Note Circle).
When written as a chord formula in relation to its own root, it takes the form 1, 3, 5, b7 - different from the I and IV chords.
Both the I and IV extend to become major 7.
Only the V chord becomes a dominant 7.
Hope that helps.
Cheers 
| Richard_close2u | JustinGuitar Official Guide & Moderator
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That does help, thanks! 
Hello mates 
,
My head got blown away by this bit
13#11b9 is a chord or a progression? And by the response of Richard above, I can see that 13, 11, and 9 are degrees of the scale that repeats themselves. However, I’m not sure why want to call chords above 8. Is it to show that we should play that chord an octave higher?
Thank you!
Hi Edgar,
Yes, it’s a chord including the 13th, the sharp 11th and flat 9th scale degree. The sharp and flat notes make it non-diatonic as a whole.
I leave the rest of the question to @Richard_close2u to answer. 
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Thank you for the clarification. What a complicated chord 
Not really. It’s a convention from how these chords can be derived.
As @Richard_close2u pointed out, triads and quadads are formed by stacking intervals of a third. If you keep on stacking 3rds in this way into the octave above, you will get 9, 11, and 13.
These are, basically, the same as 2, 4, and 6 and, in a chord, you can play the note in any octave.
Cheers,
Keith
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I am not surprised - it is …
Yes.
Building from 8 being the first octave repeat of the root note 1.
Chords that span beyond a single octave have notes that reach 8 and then higher than 8. Shall we call them ‘wide’ chords? Think of a piano keyboard and the pianists hands spread out wide to reach lots of notes.
On a guitar, chords that have notes beyond an octave happen all the time. Chords that span all six strings can have three occurrences of the root note, making these numerically 1, 8 and 15.
I will use just an E chord and variations on an E chord. This choice also means what is presented here matches with Justin’s E-shape explorer lesson: E Shape Explorer | JustinGuitar.com
To begin we will see a three octave E major scale.
Let’s consider a basic E major triad. It contains the 1, 3 and 5 of the E major scale, namely E, G# and B.
Let’s now jump directly to a ‘wide’ version of an E major, using a 6-string E-shape barre chord.
It is an E major so of course it contains the notes E, G# and B.
They appear in the ascending order E, B, E, G#, B, E.
In terms of an E major triad we know that E, G#, B can be notated as 1, 3, 5.
In this chord, strictly speaking, we do not have just 1, 3, 5.
In fact we do not have 3 at all.
Look at this repeated scale and the notes in bold, which match the barre chord above.
We have only the triad notes.
The note E is always going to be called 1st or root of the chord, even if referring to the 8 or 15.
The note B is always going to be called the 5th of the chord (even if referring to the numeric 12).
The note G# is always going to be called 3rd of the chord (even though the actual 3rd scale degree is missed and the G# does not appear until we reach numeric 10).
This chord would therefore never be called anything other than an E major chord using only the notes of an E major triad in various repeats / combinations / sequence.
To this triad based chord, other diatonic notes may be added (notes also from the E major scale).
Look at an E major 7 chord.
The additional note sits within the first octave span, it is actually the numeric 7 and the 7th scale degree. All good.
One of the three triad notes may sometimes be omitted. This happens in a sus4 chord where the 3 is removed and the 4 is used instead.
Here, the 4 is numerically the 11 as it is a note higher in pitch than the first repeat of the root note, higher than 8. It is still called the 4 and the chord is called Esus4. It is not called Esus11 because that naming does not get used. It is not called Eadd11 because the ‘add’ naming is used only when the 3 is still present within the chord. The 11 is considered as the 4.
We can look at an E add type chord.
Here we have added the note C#.
This is the 6th scale degree in the E major scale. In our numeric count it is actually 13.
The chord can be given two equally valid names, Eadd6 and Eadd13. They are interchangeable. In Justin’s explorer lesson, he chooses the first of these.
I have given a few examples to show the concept of naming chords using only triad notes plus diatonic notes and how the numeric position of the notes in terms of counting up in pitch from the lowest root note can, but does not always, have a bearing.
We can move on to the weird and the ridiculous and the chords that can come by adding non-diatonic notes.
A first obvious example would be an E dominant 7 (E7) chord.
The added note, D, is the flattened 7th scale degree of E major. I have inserted a column to accommodate this non-diatonic note.
Let’s make the big leap, if we can, directly to the E13#11b9. A monster that needs taming. Starting with the notes first this time, with extra columns to accommodate what we need.
I have gone back to using the numeric 1, 3, 5 first seen in the basic triad for simplicity. In addition to those triad notes we have
- b7 - we need this as the chord in question is some type of dominant
- b9 - named in the chord
- #11 - named in the chord
- 13 - named in the chord (a common extension of a dominant)
Oh dear. We have more than six notes! Quick - get out the Ibanez 7-string guitar. 
Or, get out the keyboard.
This chord is theoretically possible but not practical on a guitar. At least not without removing some notes. And that is possible. It is a convention that in extended chords with lots of extra notes, some can be discarded along the way. The first casualty of this sacrificial removal is the 5. It is considered non-essential in a dominant chord and is often removed. That leaves us with six notes. Can we find a position to now play the chord on the six string guitar? This may entail playing some of the notes in a different sequence to the one shown in the diagram above.
Here is one possible shape for this weird beast.
The actual sequence of ascending pitch notes looks like this:
There are some changes to the pattern shown above.
The 3 is numerically 10.
The #11 is numerically #4.
The b9 is numerically b16.
Wow.
That was longer than I thought.
And I actually decided to omit a lot of other aspects that could have been included.
I hope it helps.
Cheers 
| Richard_close2u | JustinGuitar Official Guide, Approved Teacher & Moderator
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Wow, thanks for the detailed explanation of such an ugly-sounding chord!
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For the theory experts: I read in a book on music theory that dominant chords such as D7, D9, D13 (for example) are made by successively adding notes to the previous dominant chord. That’s hard to parse, but here’s what I mean:
D7: add the b7 to the major triad: 1-3-5-b7
D9: add the 9 to the D7 chord: 1-3-5-b7-9
D11: add the 11 to the D9 chord: 1-3-5-b7-9-11
D13: add the 13 to the D11 chord: 1-3-5-b7-9-11-13
That D13 is some crazy-ass chord right there. It doesn’t seem right, but that’s what my book says. It’s pretty obvious that this is not what is done in practice on the guitar.
Anyway, if all this is right, then the E13b9#11 would (theoretically) contain:
1-3-5-b7-b9-9-11-#11-13
right? I’m going to work this into my one minute changes 
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Hi John,
The natural 9th and 11th won’t be needed as the b9 and #11 are already included in the chord. Also, the 5th can be dropped so that only 6 notes remain to play.
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yeah, that makes sense. I don’t think anybody would propose a chord with both b9 and 9 and #11 and 11 all together.
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All of this is perfectly correct.
In practice, some of the extra notes can be dropped.
Essentials that must be present are the 1, 3 and b7. Those three are enough for a dominant 7 chord and essential for any extended dominant chord.
1, 3, b7, 9 are sufficient for a dominant 9 chord.
1, 3, b7, 11 are sufficient for a dominant 11 chord.
1, 3, b7, 13 are enough for a dominant 13 chord.
Beyond these sufficient minimum four note groupings, some of the others can be included. There is no imperative to drop all but the essential notes. It is mostly done according to sound, chord voicing, ease of fingering etc.
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Very informative, thanks.
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wow Richard
many thanks for this detailed explanation. again another of your posts that will get bookmarked 
. This is good stuff 
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I was trying to figure out Dock of the Bay. According to google I guessed correctly it was in the key of G because I based my guess off the two major chords a tone apart (C and D). I believe this is what the chords should look like at Roman numerals but if I’m hoping someone can correct me if I’m wrong or give me an attaboy if I’m right.
G - I
A - II major
B7 - III 7
C - IV
D - V
D7 - V7
E - VI major
F - VII b major
The chords maybe slightly off. I learned this song years ago from one of Justin’s older lessons but it sounds pretty close when I play along with the record. Any help is appreciated.
Hello,
having solved this test mostly correct, I have one question for the question 7. (Eb Chord in the key of A). Since E is a fifth note in an A scale, I presumed a diatonic chord in the key of A should be E Major. So, since we have here Eb chord (which is also a major chord) which is obviously non diatonic, so we should just write it as flat fifth, or bV. But, in the solution it is written bVMaj. Could someone explain, why it is indicated that it should be Maj, when it is fifth chord in A scale which is major by default?
Thanx.