Triad Theory for the Beginner

Keeping it simple with the Natural Keys.

Triad Theory for the Beginner

Triad Theory in Natural Keys (no flat or sharp keys)

1 3 5 or minor 1 b3 5 also known as I iii V or i iv v in Roman Numerals. Basically Major triads have a happy or bright sound to them and minor triads have a more dramatic or sad tone to them.

All major triads are made up of the 1 3 and 5 chord tones and 1 b3 5 scale tones in minor. These numbers simply mean the number of the note in that scale. So for example in the key or scale of C Major the 1 would be the C, the 2 would be D, the 3 would be E, the 4 would be F, the 5 would be the G. The 6 would be A and the 7 would be B.

If you see a (b) before the number it means flat. Flat means you lower the note by a half step. On your instrument this would be one fret lower. So in the key or scale of C Major you have 1 3 5 (C, E and G) and in the key or scale of C Minor you have (C, Eb and G). Notice the Eb is one fret lower than the E, or (a half step) down.

Go through the chords you know and try to memorize the 3 notes the triads contain. Start with the Major ones first and then go on to the minor ones. Knowing scales and chord tones will help you create and understand music better.



D F# A

E G# B



A C# E

B D# F#


C Eb G



F Ab C

G Bb D


B D F#

About the Author:
By Mike Socarras, guitar player, teacher.

7 comments sorted by best / new / date

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    "1 3 5 or minor 1 b3 5 also known as I iii V or i iv v in Roman Numerals." Incorrect. The Roman Numerals refer to the quality of a chord and the degree in the key that it is based on. An I iii V in C major would be a chord progression which goes: C major - E minor - G major , not the notes C E G.
    Roman numerals can be used in scale degrees, however he is using them wrong. He is using them like chord numerals where you use large (III) and small (iii) to denote major or minor, however, in scales and intervals you can use I II III IV V VI VII VII (usually to denote tone, supertonic, mediant, subdominant, dominant, submediant, leading note), but instead of using lower case you would go I bIII V, not I iii V, but this is very rarely seen due to confusions between scales and chords.Though I will also add "I iii V or i iv v" is more wrong than an elderly lady in a striptease. i iv v is 1 4 5, in no way would that make sense, even a little iv, even if that meant flat 4, you would not reach a flat third, or what he is using to denote a flattened third (iii).
    I think it's a misnomer to call this triad "theory." You just identify the formula for major / minor chords and then list the notes for seven major and minor chords (i.e, excluding accidental chords like Ab major or C# minor). Why not include all 12 major and minor chords? It would just be 5 more of each. And your last sentence seems like a non-sequitur. You suddenly say how its good to know scales & chord tones, but you never said anything about scales or chord tones previously in the article. Also, confusingly, you do not mention the word "chord" at all except one place in the last paragraph... Are you using chord interchangeably with triad? This is not made clear. Since these are not (IMO) identical, I think you need to explain the distinction. Overall, it's just not written in a very clear manner that I think would be much help to any beginner guitar student (presumably the target audience).
    Gotcha, agreed. Could've been clearer. The main purpose is to know the chord tones i.e. have them memorized so that you know what you are playing. You'll know what you can sing over a certain chord, solo with. Its simply a memorization exercise especially useful for soloing. For example over a C Minor chord. Any C Eb or G will sound good. Alan, the Roman Numerals are for the chords you're absolutely right that sentence was incorrectly written.