Simply put, three note chords (like Cmaj or Fmin) are called "triads." When you add tones to the basic triad, you form "sevenths" and "ninths" and others.
Here's an easy, basic formula to help figure out 3 fingered chords to the largest 13th chord.
1. The number of notes = The type of chord.
3 notes = Triad
Four notes = Seventh
Five notes = Ninth
Six notes = Eleventh
Seven notes = Thirteenth
* Key Rule*
2. By knowing major scales, you can learn any triad, seventh, ninth, eleventh and thirteenth.
Here's the C major scale:
C D E F G A B C
To form various chords, you take notes from the C major scale. With scales, you play the notes individually, one after the other. When you're playing chords, hold down multiple notes at the same time.
To apply this simple principle, you need to convert the major scale to numbers.
C = 1
D = 2
E = 3
F = 4
G = 5
A = 6
B = 7
Now you can apply these formulas to make chords:
Major triads - 1 + 3 + 5
Minor triads - 1 + b3 + 5
Diminished triad - 1 + b3 + b5
Augmented triad - 1 + 3 + #5
Major seventh - 1 + 3 + 5 + 7
Minor seventh - 1 + b3 + 5 + b7
Dominant seventh - 1 + 3 + 5 + 7
Half Diminished seventh - 1 + b3 + b5 + b7
Diminished seventh - 1 + b3 + b5 + bb7 (think of it as "6")
Major ninth - 1 + 3 + 5 + 7 + 9
Minor ninth - 1 + b3 + 5 + b7 + 9
Dominant ninth - 1 + 3 + 5 + b7 + 9
... the same for eleventh chords, thirteenth chords, altered chords, major sixth, minor sixth, etc.
So, applying the formula in the key of C Major, the C maj chord formula is 1 + 3 + 5. The 1st tone of the C Major scale is C. The 3rd tone is E and the 5th tone is G. C major triad: C E G.
When you see the "b"... that means to lower the note a half step. If you see b3, that means to take the third tone of the scale and lower it one-half step. If a minor chord is 1 + b3 + 5, that is C Eb G, we take the third tone of the scale and lower it one-half step
Major triads: 1 + 3 + 5
Cmaj: C E G
Minor triads: 1 + b3 + 5
Cmin: C Eb G
Diminished triad: 1 + b3 + b5
Cdim: C Eb Gb
Augmented triad: 1 + 3 + #5
Caug: C E G#
Major seventh: 1 + 3 + 5 + 7
Cmaj7: C E G B
Minor seventh: 1 + b3 + 5 + b7
Cmin7: C Eb G Bb
Dominant seventh: 1 + 3 + 5 + b7
C7 (Cdom7): C E G Bb
Half Diminished seventh: 1 + b3 + b5 + b7
C half dim7: C Eb Gb Bb
Diminished seventh: 1 + b3 + b5 + bb7 (think of it as "6")
Cdim7: C Eb Gb A
3. You can play 9th, 11th or 13th chords by knowing seventh chords.
The major ninth chord is:
1 + 3 + 5 + 7 + 9. The Cmaj9 chord is C E G B D. A shortcut is to play Emin7 over C.
C/EGBD = Cmaj9. How can we make apply this to all maj9 chords?
4. Take the iii min7 of any major key.
1. Start with the keynote of the major scale. If you want to play a Cmaj9 chord, the keynote would be "C". Play this on on your left hand.
2. With the r.h., locate the 3rd tone of the scale and play a minor seventh chord on that tone. In the key of C, the 3rd tone is E. So, you would play an Emin7 chord on C bass.
Here's a list of all twelve major ninth chords:
Cmaj9: C + Emin7 (C E G B)
Fmaj9: F + Amin7 (F A C E G)
Bbmaj9: Bb + Dmin7 (Bb D F A C)
Ebmaj9: Eb + Gmin7 (Eb G Bb D F)
Abmaj9: Ab + Cmin7 (Ab C Eb G Bb)
Dbmaj9: Db + Fmin7 (Db F Ab C Eb)
Gbmaj9: Gb + Bbmin7 (Gb Bb Db F Ab)
Bmaj9: B + D#min7 (B D# F# A# C#)
Emaj9: E + G#min7 (E G# B D# F#)
Amaj9: A + C#min7 (A C# E G# B)
Dmaj9: D + F#min7 (D F# A C# E)
Gmaj9: G + Bmin7 ( G B D F# A)
Minor Ninth Chords
Minor ninth chords have a similar formula. Instead of taking the 3rd tone of the scale and playing a minor 7th chord on it, simply take the b3rd of the scale and play a major 7th chord on it. It's kind of like the opposite of the maj9 chord.
Maj9 vs Min9
Maj9: Take the 3rd tone of the scale and play its minor seventh chord.
Min9: Take the b3rd tone of the scale (or the relative major) and play its major seventh chord.
1. Start with the keynote of the major scale. (Let's use C)
2. With the r.h., locate the b3 tone of the scale. Find the natural third tone (E) and lower it one-half step to Eb. The b3 of Cmaj is Eb.
3. Play Ebmaj7 over C bass and there's a nice min9 chord.
Cmin9: C + Ebmaj7 chord (C Eb G Bb D)
For more information, learn about the 9th chord.
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