If you learn three popular chords, there are probably a few hundred tunes you can play. On the guitar or piano, if you learn E, A and B7 you have those three chords. If you change the key because you want to sing higher or lower, you could play C, F and G7 or G, C and D7.

In this article we’ll look at the mysterious 7th chord – chords like B7, G7 and D7. Why do we have 7ths and what do they do?

Let’s take the chord sequence G, C and D7 as an example. If you start a song by playing a G chord, that chord feels like “home.” You start from home, go on a journey by playing some other chords – in this case you might play G for a bit, then a C chord for a bit, back to G, back to C, then finally D7, which brings you home again to a G chord.

Simplified, it might be G, then C, then D7, then G.

The G is home. It’s comfortable; stable.
The C helps you travel. It’s also pretty comfortable.
The D7 is a chord of change, it wants to go somewhere (usually back home).

Music and songs tell a story that includes both tension and resolution. Without tension you’d have a boring story. So your chords start from home, something interesting happens, then they come home again.

7th chords add tension. They’re always going somewhere, doing something. They’re chords of CHANGE.

During the middle ages, the church actually banned their use, and they were called “the devil’s chord.” This is probably because they contain an interval of tension. In music terms they contain an interval of six ½-steps. If you have a D7 chord, you have the notes of D-F#-A-C. The tense interval happens when you play F# and C. Because your ear want to resolve that tension, it wants to change the F# to a G, and the C to a B. That’s why the tense chord of D7 resolves (or goes “home”) to a G chord. That is: two of the notes of the D7 that are tense, want to resolve to two of the notes of a G chord, which is a resolution or comfortable chord.

It’s tension and resolution that make music interesting.
And it’s tension and resolution that make life interesting.

As an experiment, play a D7 and then a G. Listen to how the D7 (a chord of change) naturally resolves to a G chord.
Try G7 to C, or B7 to E.

The 7th chord adds interest and only temporarily feels tense, but the tension is what tends to bring you home. In a way, it’s a comforting thought that when you have tension in your life, it adds a bit of interest, just like a 7th chord. And in the same way, if you look for where you are being “moved” to, by asking what you are learning – you can begin to see what that tension is teaching you, and that it’s really bring you “home.”

While the church may once have been uncomfortable with 7ths because they were chords of change, 7ths are now standard, embraced, and even loved.

What would happen if instead of feeling uncomfortable with tension, you embraced it, because musically, and in life, tension can be so very close to resolution? And after all, it does add interest to life.

All the best,


Allan,
BellaOnline’s Musician Editor