Basic Chord Theory I

This is the first lesson of the series, and will show the basic theory behind major, minor, augmented, and diminished triads. Enjoy!

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Intro: Hello, and welcome to a series of CPDmusic lessons. I had a request to do a lesson on guitar chords, so I decided to write a series on basic chord theory. This is the first lesson of the series, and will show the basic theory behind major, minor, augmented, and diminished triads (triads are three note chords). Enjoy! The Major Triad: Lets start by learning a pretty basic chord, a major triad. In this example, we will construct a C major triad. To start, we would take the root note, in this case C:
E||-------||
B||-------||
G||-------||
D||-------||
A||--3----||
E||-------||
From there, the next note would be a major third from the root note, in this case E:
E||-------||
B||-------||
G||-------||
D||--2----||
A||--3----||
E||-------||
The final note in a major triad is a perfect fifth from the root note. An easier way to remember this, which was suggested in the comments of one of my previous lessons, is to look at all the notes in thirds. So, instead of looking at the third note as a perfect fifth from the root note, we could also look at it as a minor third of the second note. Either way, the final note is G:
E||-------||
B||-------||
G||--0----||
D||--2----||
A||--3----||
E||-------||
And there you have it, a C major triad! Now, there are a few ways to express this triad, as with all chords, in a sort of equation. The most common one would probably be like this: 1 3 5 It may just look like random numbers right now, but really, it is the key to the major triad! Those numbers are in relation to the major scale. Each number represents a note, and the number tells you what notes make up that specific triad. For example, lets use this system with our C major triad. Since our triad is in C, we would compare those numbers to the C major scale, that being C D E F G A B. The first note is the number one, meaning it's the first note or the scale, or C. The second and third notes are the third and fifth notes of the C major scale, or E and G respectively. An important thing to remember is that it is ALWAYS in relation to the major scale, even with minor triads. ALWAYS. Now, to wrap things up, I should probably shed some light onto what this is a major triad. The reason that it is a major triad is because it has major intervals. The major third in the triad is really all that separates it from a minor triad. The Minor Triad: Now, the minor triad only has one note that is slightly changed from the major triad. The minor triad goes like this: 1 b3 5 It has the 1 and the 5 like the major triad, but the 3 is flattened, meaning it is lowered by one semitone. So, lets use this knowledge to construct a C minor triad! First, we will start with C:
E||-------||
B||-------||
G||-------||
D||-------||
A||--3----||
E||-------||
Now, the third note of the C major scale is E. But, in the minor triad, the E is flattened to a Eb:
E||-------||
B||-------||
G||-------||
D||--1----||
A||--3----||
E||-------||
And then finally, we would add the perfect fifth, or 5, to the now completed triad, in this case being G:
E||-------||
B||-------||
G||--0----||
D||--1----||
A||--3----||
E||-------||
So, there is our C minor triad! Pretty easy, eh? Examining it, you will notice that when compared to the C major triad, there is only one note that is different, and only by one semitone. This is how the major and minor triads differ, and the ONLY way. While a major triad is root, MAJOR third, perfect fifth, a minor triad is root, MINOR third, perfect fifth. Do you see the pattern? The Augmented Triad: The next triad we are going to learn is the augmented triad. It also differs from the major triad by only one note. An augmented triad goes like this: 1 3 #5 So, this means we would take the natural first and third note from the major scale, and the sharpened fifth note from the major scale, to make an augmented triad. So, lets use this to construct a C major triad, starting with the root note C:
E||-------||
B||-------||
G||-------||
D||-------||
A||--3----||
E||-------||
Next, we would add the major third, which would be E:
E||-------||
B||-------||
G||-------||
D||--2----||
A||--3----||
E||-------||
Finally, the fifth note of the C major scale is G. But, the augmented triad has a sharpened fifth, making the last note in the triad G#:
E||-------||
B||-------||
G||--1----||
D||--2----||
A||--3----||
E||-------||
So there is our C augmented triad. The reason this triad is called an augmented triad is because of the augmented fifth. An augmented fifth is a perfect fifth that has been raised by one semitone, that being the #5 in the above numerical sequence. This augmented fifth gives the augmented triad a bit more of a tense sound to it. The Diminished Triad: Now it's time for the final chord of this lesson, the diminished triad. This one is a bit different that the other triads we've learned thus far, as it has two altered notes in comparison to the major triad and scale. The diminished triad goes like this: 1 b3 b5 As you can see, this chord has two flattened notes. So, lets look at how to construct a C diminished triad, once again starting with the root note:
E||-------||
B||-------||
G||-------||
D||-------||
A||-------||
E||--8----||
The reason I put the C on the E string this time is because if we put it on the A string, we wouldn't be able to make the triad, because the b5 has to go on the D string. If we were to play the C on the E string, we would have to add a second C in between the Eb and Gb. (I will get into this in a later lesson). Next, we would add the b3. The third note of the C major scale is E, meaning the b3 in C would be Eb:
E||-------||
B||-------||
G||-------||
D||-------||
A||--6----||
E||--8----||
Finally, we would add the b5, which would be Gb:
E||-------||
B||-------||
G||-------||
D||--4----||
A||--6----||
E||--8----||
And there is a C diminished triad! The reason this triad is a diminished triad is because of the two diminished intervals, the diminished third and diminished fifth. These are the b3 and b5 in the above numerical sequence. Outro: So, that's all for today's lesson! Today, we learned the basic chord theory between major, minor, augmented, and diminished triads, which is important to learn early. Just to review: Major = 1 3 5 Minor = 1 b3 5 Augmented = 1 3 #5 Diminished = 1 b3 b5 And remember, those numbers are in relation to the major scale, no matter what. So, hopefully you enjoyed that lesson. One final thing, if you go to my YouTube channel here you can find a chord identification training video, which you can use to aid in identifying major, minor, and augmented chords by ear. Enjoy! Did You Like This Lesson? Check Out All My Lessons Here. More Lessons Coming Soon!

21 comments sorted by best / new / date

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    wjviper6
    Great lesson but I noticed something that was wrong right before the outro. "And there is a C diminished triad! The reason this triad is a diminished triad is because of the two diminished intervals, the diminished third and diminished fifth. These are the b3 and b5 in the above numerical sequence. " It is a minor third, not a diminished third. A diminished third would actually be another half step down from what you want. The way I remember what makes up a diminished triad is that it is two minor thirds on top of your root noot (or a minor third and a diminished fifth.)
    yudha007
    thx , it's so interesting and helpful for me. especially for the beginner like me thank you very much
    Blunk182
    I looked at this on a whim and was really glad I did. Previously being a bass player I never learned the chord theroy and this realy helped. 10/10 Thank You!
    mcflaps
    good job man help alot, but where can i find all major and minor scales??
    CPDmusic
    Lost&FoundBox wrote: Great lesson!!! Im pretty much a noob so im limited in my knowledge of theory... But i just wanted to say thank you for the lesson it helped mostly. But i still have a question... how does this apply to understanding weither a chord is played full (all strings) or if it has to have certain strings muted? All in all... Id give this lesson a 9 outta 10... only cause not enough info on playin the chord once constructed. Thanks for the lesson again. keep them coming there helping alot!
    It doesn't really matter, as long as your hitting all of and only the notes in the designated chord, you can play three strings, four string, five strings, six strings... the harmonies will still be there, playing more strings will really just change the fullness of the chord.
    Lost&FoundBox
    Great lesson!!! Im pretty much a noob so im limited in my knowledge of theory... But i just wanted to say thank you for the lesson it helped mostly. But i still have a question... how does this apply to understanding weither a chord is played full (all strings) or if it has to have certain strings muted? All in all... Id give this lesson a 9 outta 10... only cause not enough info on playin the chord once constructed. Thanks for the lesson again. keep them coming there helping alot!
    CPDmusic
    leenux5030 wrote: I am a total noob, I am not able to relate this with A maj chord, which as per my knowledge is : E||-----|| B||--2-----|| G||--2-----|| D||--2----|| A ||--0----|| E||-----|| . can you explain me this chord, that will be a great help Thank you
    We know that a major chord is 1 3 5, so if we took the A major scale (A B C# D E F# G# A) and took the first, third, and fifth notes of it, we would get A, C#, and E, meaning as long as the chord has all of those notes, and only those notes, it is A major. The chord you posted follows this order: A E A C#. It has only the notes A C# and E, making it A major. Hopefully that helped.
    lazlong
    Thanks for posting your lessons on chords. Starting with a simple C major triad certainly simplifies things. Of course, these shapes can be used all over the fretboard, provided it's kept above the B string.
    SilverSpurs616
    Nothing new for me but I enjoyed reading it anyway this should be a perfect introduction to any musican learning about chords! Good job, looking foreward to more
    CPDmusic
    aCloudConnected wrote: Perfect for anyone who's just getting into theory. I hope the next lesson is about when it's appropriate to apply these chords?
    Actually, I intended to make the next lesson about throwing sevenths into the mix, and maybe basic suspended chords, but I could write a lesson on application too
    aCloudConnected
    Perfect for anyone who's just getting into theory. I hope the next lesson is about when it's appropriate to apply these chords?
    zgbgydug
    I think this is great help for any beginners. Instead of looking up every single chord, you can look up one and know four.
    nbur4556
    I pretty much new all this stuff already, but not very well so it was a great review! I'm gonna read your 2nd lesson on this in a minute, also, did you ever end up making a lesson on when to apply it (mentioned earlier)
    leenux5030
    I am a total noob, I am not able to relate this with A maj chord, which as per my knowledge is : E||-----|| B||--2-----|| G||--2-----|| D||--2----|| A ||--0----|| E||-----|| . can you explain me this chord, that will be a great help Thank you
    flava14
    Dude, this is fantastic. This is what i have been asking soo many other guitarists and huitar teachers over the last year. That being how is a chord made and why is it made with the following notes. I can't wait to use them and start making my own shapes up. Should come in handy for jazz band
    CPDmusic
    nbur4556 wrote: I pretty much new all this stuff already, but not very well so it was a great review! I'm gonna read your 2nd lesson on this in a minute, also, did you ever end up making a lesson on when to apply it (mentioned earlier)
    Not yet, I want to teach as many chords as I can first.
    MSJChE
    Interesting how you use a visual interval approach on the fret board.