What is a seventh chord?
To benefit from the information in this article, you have to understand what a chord is and how to form one. We’ll run through this quickly now, but be sure to check out this article on harmony if you want to get a more in-depth look into this concept.
A chord is what happens when you play multiple notes at the same time. We have a standard way of making chords by taking alternating notes from a scale and stacking them on top of each other.
At its core, a seventh chord is a four-note chord built by stacking these intervals above a “root note” (that just means the note you’re starting with). While a basic triad consists of three notes (root, third, and fifth), a seventh chord adds a fourth note: a seventh interval above the root. This additional note adds colorful harmonic texture and opens up new possibilities for writing chord progressions and voice leading.
Let’s use the example of a C major scale to outline this idea. This scale has the notes C, D, E, F, G, A, B in it. To get a C major triad, we’ll take the first note of the scale (C), skip the next note, use the one after that (E), and repeat with the next notes. Therefore the C major triad consists of the notes C, E, and G. That sounds like this:
