Hey everyone! 
We had so many great questions during the session — we didn’t manage to get through them all, but please keep them coming and post them here. 
Recording will be posted here right after the session: https://www.justinguitar.com/live-events/237
Just watching the replay. Couldn’t get any of the 1 4 5 chord progressions by ear. Very disheartened.
Like Justin said, keep working on it, things will start to happen 
I just wathe it too, and got the earlier one but not the latter with the octave I. Work in progres i think
This was a really great class! I learned a lot.
One thing that I need some help with regarding a key. Can someone clarify the relationship between the following:
Tone - tone - semi tone - tone - tone - tone - semitone
I - II - III - IV - V -VI - VII - I
Major - minor - minor - major - major - minor
If I use C as an example, we get:
C - D - E - F - G - A - B - C
I (C) - II (D) - III (E) - IV (F) - V (G) - VI (A) - VII (B) - I (C)
Major (C) - minor (E-) - minor (F#-) - major (G) - major (A) - minor (B-)
Why does the last pattern have minor chords and what is the relationship to the key signature? I’m trying to get the “why” so I can do the how.
Thanks
I will make several answers, short and long.
Short [1 of 1]
Just as the notes within a major scale follow TTSTTTS so the chords follow a set pattern of Maj-min-min-MAJ-MAJ-min-dim
That happens through a process called harmonising the major scale - stacking notes in thirds until a triad is formed.
Long [1 of 2]
Harmonising the D Major Scale
We will work through the entire process of harmonising the D Major scale to create all seven chords within the key of D Major.
1] D Major chord = D - F# - A
The interval from Root to 3 is four semitones - this is a Major third so the chord is D Major.
2] E minor chord = E - G - B
The interval from Root to 3 is three semitones - this is a minor third so the chord is E minor.
3] F# minor chord = F# - A - C#
The interval from Root to 3 is three semitones - this is a minor third so the chord is F# minor.
4] G Major chord = G - B - D
The interval from Root to 3 is four semitones - this is a Major third so the chord is G Major.
5] A Major chord = A - C# - E
The interval from Root to 3 is four semitones - this is a Major third so the chord is A Major.
6] B minor chord = B - D - F#
The interval from Root to 3 is three semitones - this is a minor third so the chord is B minor.
7] C# diminished chord = C# - E - G (the awkward diminished chord)
The interval from Root to 3 is three semitones, this is a minor third BUT this is a C# diminished chord, not C# minor. This is due to the distance between its Root and 5 also being a minor third. The six Major and minor chords have an interval of a ‘perfect fifth’ (seven semitones) between their Root and 5. This diminished chord is unique in having a ‘diminished fifth’ interval (six semitones) between them.
Long [2 of 2]
Consider G major - using the major scale formula:
Tone Tone Semitone Tone Tone Tone Semitone or
Whole Whole Half Whole Whole Whole Half
We get these seven notes:
G A B C D E F#
String several octaves together and you have:
G A B C D E F# G A B C D E F# G A B C D E F# G …
The chords in the key, derived from the scale (called the diatonic chords) are found using a process called ‘harmonising the major scale’. These chords will all be triads (three note chords).
Chord I
Root note = G
G A B C D E F# G A B C D E F# G …
Counting:
1, 3, 5 = G, B, D
Chord = G Major
Chord ii
Root note = A
A major scale = A, B, C#, D, E, F#, G#
Counting:
1, 3, 5 = A, C#, E
BUT
C# is not a note in the G major scale (the scale we are harmonising). The only note with a ‘C’ in its name in the G major scale is C natural. And we need to use only the notes in the G major scale when harmonising the G major scale. Therefore, this third note from our counting must be ‘flattened’ to match the notes found in the G major scale.
So, instead of
1, 3, 5 = A, C#, E
G major scale has
1, b3, 5 = A, C, E
Chord = A minor (a flat 3rd note makes a minor chord)
Chord iii
Root note = B
B major scale = B, C#, D#, E, F#, G#, A#
Counting:
1, 3, 5 = B, D#, F#
BUT
D# is not a note in the G major scale (the scale we are harmonising). The only note with a ‘D’ in its name in the G major scale is D natural. And we need to use only the notes in the G major scale when harmonising the G major scale. Therefore, this third note from our counting must be ‘flattened’ to match the notes found in the G major scale.
So, instead of
1, 3, 5 = B, D#, F#
G major scale has
1, b3, 5 = B, D, F#
Chord = B minor (a flat 3rd note makes a minor chord)
Chord IV
Root note = C
C major scale = C, D, E, F, G, A, B
Counting:
1, 3, 5 = C, E, G
Chord = C Major
Chord V
Root note = D
D major scale = D, E, F#, G, A, B, C#
Counting:
1, 3, 4, = D, F#, A
Chord = D Major
Chord vi
Root note = E
E major scale = E, F#, G#, A, B, C#, D#
Counting:
1, 3, 5 = E, G#, B
BUT
G is not a note in the G major scale (the scale we are harmonising). The only note with a ‘G’ in its name in the G major scale is G natural. And we need to use only the notes in the G major scale when harmonising the G major scale. Therefore, this third note from our counting must be ‘flattened’ to match the notes found in the G major scale.
So, instead of
1, 3, 5 = E, G#, B
G major scale has
1, b3, 5 = E, G, B
Chord = E minor (a flat 3rd note makes a minor chord)
Chord vii
Root note = F#
F# major scale = F#, G#, A#, B, C#, D#, E#
Counting:
1, 3, 5 = F#, A#, C#
BUT
Neither A# nor C# are notes in the G major scale (the scale we are harmonising). The only notes with ‘A’ or ‘C’ in their names in the G major scale are A natural and C natural. And we need to use only the notes in the G major scale when harmonising the G major scale. Therefore, this third note and the fifth note from our counting must be ‘flattened’ to match the notes found in the G major scale.
So, instead of
1, 3, 5 = F#, A#, C#
G major scale has
1, b3, b5 = F#, A, C
Chord = F# diminished (a flat 3rd note and a flat 5th note makes a diminished chord)
Disclaimer: I only know just enough about theory to be dangerous. I could be wrong but this is how I think about it.
TTSTTTS gives you the notes in the scale.
Maj Min Min Maj Maj Min gives you the chords in the key.
Absolutely epic Richard. Thank you. This has unlocked a major level of understanding that I could not get past even with my in person teacher. The visuals really helped.
Love this Chris. Every complex pattern has to be accessible esp. when playing! I’m gonna steal this with pride. 
Hi @Richard_close2u, instead of invoking the major scale for each chord, wouldn’t it be easier to work with the notes of the major scale of the key you are in. So, instead of going through the A major scale and adjusting the sharps and flats, why shouldn’t I just take the G major scale, start on the note A and use the pick one/skip one,… formula. This immediately gives A, C, E without any adjustments needed.
Likewise for all the other chords: all you need is the G major scale and the pick one/skip one rule and you generate all the chords in the key. It seems a lot simpler to me.
John, that is exactly the procedure I followed in long answer 1 of 2. The graphics show exactly what you ask about. All seven chords are created from the D major scale with three iterations of pick one / skip one. The graphic also shows, proptionally in width, why some are major and some are minor (plus diminished of course).
Long answer 2 of 2 is an alternative and depicts a complementary, not rival, procedure whereby reference is made to the major scale of each new root note in turn.
They are two perspectives on the same thing.
