Hey Friend,
I’m sure you’ve seen them before. You find some tabs online that show a simple chord chart, and in that chart you see chords listed like this:
A7 D7 E7…
What the heck are those?
These are known as “7” chords - those specifically are “Dominant 7” chords.
A 7 chord takes the normal major or minor chord shape and adds the 7 note of the scale to the chord. That means the chord is no longer just a triad - it now has four notes.
There are three forms of 7 chords - Dominant, Major and Minor. Two of these forms use the 7m note (minor 7) from the scale, and one uses a major 7 note - can you guess which one?
Nope, not a trick question. That’s right, the Major 7 chord (7M) uses a major 7 note, while the dominant and minor 7 chords use the 7m note from the scale. But here’s an interesting twist… The dominant 7 chord is a major chord plus the 7m note. A minor 7 chord (m7) is the minor chord plus the 7m note.
Major 7 - major chord plus 7 note (7M) Dominant 7 - major chord plus 7m note (7)
Minor 7 - minor chord plus 7m note (m7)
Let’s quickly look at an example. Here’s a C major scale:
1 2 3 4 5 6 7 (8)
C D E F G A B (C)
A C major chord is notes C E G. If you want to make the C chord a C7 (C Dominant 7), you simply add the 7m note from the same scale. That would be the Bb (B flat) note. So a C7 chord is a combination of notes C E G Bb.
A Cm7 (C minor 7) is a Cm chord plus the Bb note (7m): C Eb G Bb
For a CM7 (C major 7), take your C chord and just add the 7 note: C E G B
The most commonly used form is the Dominant 7 chord. Whenever you hear 12-barre Blues, you are most likely hearing dominant 7 chords in it, but Rock uses these almost every time a 7 chord is needed.
Major and minor 7 chords are used a lot in Jazz and Soul, but I like them a lot and they work their way into stuff I write.
And with that, I've run out of time. Time to get ready to face the world. Catch you tomorrow.
Peace~
Dave
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