How to go from triads (3 notes) to 7th chords (4 notes), making a world of difference!
By Jon Liebman
August 8, 2024
In last week’s lesson, we went over how to find additional “right” notes to enhance our bass lines (as needed) by building a triad on each note of a major scale.
For our example, we used an “A” major scale. We talked about how chords are built in thirds and how our triads can be either major or minor, depending on which notes of that triad are in the scale.
In this lesson, part 2, we’re going to go one step further by adding a 7th to each chord.
For most of the chords in this example, we’ll continue adhering to playing only the notes in an “A” major scale. In a couple instances, however, we’re going to “break a rule” and play a note that’s not in the scale.
The two exceptions are on the “A” and the “D” chords, where, in both cases, we play a minor 7th instead of a major 7th.
Specifically, in the “A” chord, we play our triad (A-C#-E), then, for the 7th, instead of playing a “G#” (a major 3rd up from “E”) which is in the key of “A”), we play a “G” natural, which is not in the key of “A.” The result is an “A7” chord (A-C#-E-G), also known as a “dominant” 7th.
Similarly, on the “D” chord, we play our triad (D-F#-A), then for the 7th, instead of playing a “C#” (a major third up from “A”), we play a “C” natural, resulting in a “D7” chord: D-F#-A-C.
This type of exception is very common in all kinds of music, including rock, pop, blues, jazz… Just remember, whenever you see a dominant 7th chord (e.g., A7, D7, Bb7, F#7), stay away from the major 7th in each chord. If you do play a 7th in your bass line, make sure it’s the minor 7th.
In other words, the notes that make up an “A7” chord are: A-C#-E-G.
A “D7” chord: D-F#-A-C
A “Bb7” chord: Bb-D-F-Ab
A “C7” chord: C-E-G-Bb
Take a look at the video to get a better understanding of how this works. Then see what you can come up with on your own.
Be sure to leave a comment and share your experience. I’d love to know your take.
Let’s play bass!
Jon
