(13 Jan 03)
Seventh chords are a continuation of the theory of Intervals and Triads. I therefore strongly recommend that you have good knowledge about these topics. Refer to the articles "Intervals or the Key to Harmonic Understanding" and "Triads - The First Chords" for further information.
Depending on how much you know about 7th chords, the information in this article may not be very earthshaking. Talking about music theory is, on the one hand, a presentation of plain facts that someone has to learn and understand. On the other hand I will point out some practical things that apply both to musical arrangers as well as instrumentalists.
Although the 'hands-on' section of this article targets guitar players I strongly recommend that you try to apply the theory to any other instrument (preferable piano), as the introduced voicing techniques are the basis for any other harmonisation, e.g. a horn section.
The article is divided into two parts. The first part is focussed entirely on the major seventh chord explaining seventh chord theory and voicing techniques.
The second part is meant to be a "do it yourself" section. I encourage you to take the knowledge of the first part and apply it to the second part on your own.
It would be preferable if you have notation paper and a kind of tab paper as working tools. The last page of this article offers a tab template that you can print out and use for drawing the different voicings.
At the end of this article I have a little reward for all your efforts.
Ready, aim, fire ...
7th Chord Theory
A 7th chord is constructed by adding another third to a triad. The result is a 4 note voicing stacked up in thirds.
As a first example let's take a C major triad and add another third on top of it. We have two choices. Either we add a major third or a minor third. In both cases we will end up with a seventh chord.
C major triad + major third
The added note is B and is the major seventh of C.
C major triad + minor third
The added note is Bb and is the minor seventh of C.
Todays music distinguishes between five main chord families and seventh chords.
minor seventh flat five