Guitar Lesson – Music Theory Part 6 – the other numbers
The 6th chord is simply the normal triad with an added 6th. For C, this would mean the notes are: C E G A.
The 7th chord is simply the normal triad with an added 7th. Normally, if it just says “7” as in C7, the “7” refers to the minor 7th. So C7 has: C E G Bb. You can also add the 7th to the minor chord. Cm7 would be: C Eb G Bb. The major 7th can also be used but it’s normally written as “maj7“. Cmaj7 would be: C E G B.
The last number we’ll talk about for this lesson is the 9. As you may recall, the 1 and 8 notes are the same note except the 8th is an octave above the 1. The 9th is therefore the same note as the 2nd also an octave above.
For 9, there are 4 chords worth mentioning…
“9” — This is not the same as “add9”. In this case, the minor 7th is implied. So the notes for C9 are: C E G Bb D.
“maj9” — In this case, the major 7th is implied and so Cmaj9 would be: C E G B D.
“min9” — Very similar to the “maj9”, here the minor 7th is implied and so Cmin9 would be: C Eb G Bb D.
There are also 11th and 13th chords but we’ll look at them another time.
In one of the next posts, we’ll look at how these chords might be used.