Chord Formulas
Chord formulas refer to the actual notes being played in a chord and associates the numbers (1 through 8 ) of the major scale to those notes. Actually sometimes we repeat the scale an octave higher and continue counting up to number 13.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
| C | D | E | F | G | A | B | C |
Major Chords. For example, the C major chord is comprised of the notes C, E and G. When we look at the C major scale, we notice that these are notes numbered 1, 3, and 5. We then can deduce that the ‘chord formula’ of the major chord is 1,3,5. If we want to know the notes of any major chord, we can jump to that chord’s major scale and find notes 1,3,5 and know which notes we are playing. Thus the G chord is played by notes G, B, D. The D chord is comprised of notes D, F#, A. Etc.
Minor Chords. A minor chord takes the the 3rd note of the major chord and “flats” it, or lowers it a half step. It’s chord formula is 1,♭3,5. We can look at the C scale, and take the notes C, E♭, and G. ‘E’ is the 3rd note which gets “flatted”, and becomes an ‘E♭’ to make the Cm chord. The Dm is comprised of notes D,F,A.
Other Chord Variations. Sometimes we see chords like C2, Csus, C6, C7, Cm7, Cmaj7, Cmaj9, Cadd9, etc. These notations refer to special ways of handling the numbered notes of the chord’s major scale. Look at the following chart:
| Suffix | C Variation | |||
| (none-major) | 1,3,5 | C | C,E,G | |
| 2 or sus2 | 1,2,5 | C2 or Csus2 | C,D,G | |
| sus or sus4 | 1,4,5 | Csus or Csus4 | C,F,G | |
| 6 | 1,3,5,6 | C6 | C,E,G,A | |
| maj7 | 1,3,5,7 | Cmaj7 | C,E,G,B | |
| 7 | 1,3,5,♭7 | C7 | C,E,G,B♭ | |
| add9 | 1,3,5,9 | Cadd9 | C,E,G,D | |
| m | 1,♭3,5 | Cm | C,E♭,G, | |
| m6 | 1,♭3,5,6 | Cm6 | C,E♭,G,A | |
| m7 | 1,♭3,5,♭7 | Cm7 | C,E♭,G,B♭ | |
| 5 | 1,5 | C5 | C,G |
See the next section, What Am I Playing on the Guitar?, to see how an example of how to incorporate chord formulas with chords you may already know.
Hi,
I’m confused with Chord Families (Major) where I, IV, V to be played.
But, in this page, you mention 1,3,5 as a Major Chord.
What are these two? pls explain.
The Roman numerals stand for the chords in a key. Arabic or regular numbers represent the NOTES in a chord. When looking for notes in a chord, find that chord’s major scale, number the notes, and take notes 1, 3, and 5. For G we get G A B C D E F# G. If we number these, then the notes in spots 1, 3 and 5 are the notes that make up the G major chord. These notes are G, B and D.
If, however, we are searching for the major chords in the key of G, we still use the G major scale, and number the notes. We look at the notes in spots 1, 4 and 5. These indicate which chords are major in the key of G. Chords G, C and D are major. And we use roman numerals when referring to them as chords: I, IV and V. Incidentally, 2, 3 and 6 indicate the chords that are minor in the key. So in the key of G, they would be Am, Bm and Em, and we number them with lowercase roman numerals, ii, iii, and vi.
Does this help?
David
thank u very much brother