Part 3: Chords with more than three notes
So far, we’ve looked at notes within the root and the 5th – chords with two or three notes. Now let’s look at notes beyond the 5th. You’ll see that they’re all based on the 3-note chords from the previous section.
1-3-5-b7. At this point, it becomes increasingly important to keep your suffixes straight. “C” is C major, but “C7” is not C major 7 (Cmaj7 is shown next). C7 is usually followed by an F chord. Generally you’ll see C7 when you’re playing in the key of F. In the key of D, you might see A7. Key of G: D7. Key of E: B7, and so on.
1-4-5-b7. In our style, we almost always avoid C7 (or G7, or A7, or D7… you get the idea). Instead, we use Csus7. You can see that it’s just a Csus chord with an added b7. It has the same function as the C7, but a slightly different sound.
1-3-5-7. The C major 7 is a C chord with an added 7. Notice that it’s different from C7 – a tiny change in pitch will give you a very different chord!
1-b3-5-b7. C minor 7 is a C minor chord with an added b7.
Cdim7 or C°7
1-b3-b5-6 (actually 1-b3-b5-bb7). The C diminished 7 chord is more common in classical music, but it can be a very expressive harmony to use in certain situations, even in a contemporary style.
The dim7 chord requires a little explanation. It’s a Cdim chord plus a diminished 7th. A diminished 7th is a half-step lower than a b7. It should actually be written as a bb7:
But the bb7 (“double flat) is the same thing as a 6. So the chord could also appear like this:
1-3-5-6. A C6 chord is just like a C major chord, but with an added 6.
Occasionally, you’ll see ninth chords: C9, Cmaj9, Cm9, C6/9. They’re just like their lesser counterparts, but with an added ninth above.
Here’s the piano graphic for the C9. The rest you should be able to figure out:
Next: Chord alterations