Tetrachords are groups of four notes that make up half of a scale. You can combine two tetrachords to form any of the common jazz scales (through you may need to add a doubled root for a 9-note scale like a diminished or bebop scale).
In Part 1, we learned about the different types of tetrachords. In part two, we will learn to combine these tetrachords into full scales!
Here are some important points to remember from Part 1:
- A tetrachord is a group of four pitches within the span of 6 half-steps (the interval of a tritone).
- Tetrachords make up a mini-scale. Tetrachords can actually be thought of as HALF of a scale. Most of the scales jazz musicians typically use are made up of two tetrachords.
- To combine two tetrachords into a scale, you’ll start the first tetrachord on the root. You’ll start the second tetrachord on the 5th OR the #4/b5.
All of these tetrachords are comprised of half-steps (H), whole-steps (W), and minor thirds (b3). Here’s a quick review of the different types of tetrachords from Part 1:
All of these tetrachords are comprised of half-steps (H), whole-steps (W), and minor thirds (b3).
- The Major Tetrachords is 1234. The intervals are WWH.
- The Minor Tetrachord is 12b34. The intervals are WHW.
- The Phrygian Tetrachord is 1b2b34. The intervals are HWW.
- The Whole Tone (or Lydian) Tetrachord is 123#4. The intervals are WWW.
- The Diminished Tetrachord is 1b2b33. The intervals are HWH.
- The Harmonic Tetrachord is 1b234. The intervals are Hb3H
- The Mixolydian Blues Tetrachord is 12b33. The intervals are WHH.
- The Blues #1 Tetrachord is 1b34#4. The intervals are b3WH.
- The Blues #2 Tetrachord is 1b23#4. The intervals are Hb3W.
- The Chromatic Tetrachord is 1b22b3. The intervals are HHH.
Now that we’ve reviewed the different types of Tetrachords from Part 1, let’s learn how to make the 16 Most Important Scales in Jazz using Tetrachords! Here is a PDF of the 16 most important scales in jazz and their corresponding tetrachords:
Using Tetrachords Make Scales Bass Clef
Here is a Quick Summary of how to form scales using tetrachords:
1. Major Scale-Major tetrachord, major tetrachord on 5th.
2. Dorian Scale-Minor tetrachord, minor tetrachord on 5th.
3. Phrygian Scale-Phrygian tetrachord, phrygian tetrachord on 5th.
4. Lydian Scale-Whole Tone tetrachord, Major tetrachord on 5th.
5. Mixolydian Scale-Major tetrachord, Minor tetrachord on 5th.
6. Natural Minor (Aeolian) Scale-Minor tetrachord, Phrygian tetrachord on 5th.
7. Locrian Scale-Phygian tetrachord, Whole Tone tetrachord on flat 5th.
8. Half-Whole Diminished (Dominant-Diminished) Scale-Diminished tetrachord, Diminished tetrachord on flat 5th, extra root at top.
9. Whole-Half Diminished (Diminished-Diminished) Scale-Minor tetrachord, Minor tetrachord on flat 5th, extra root at top.
10. Altered Scale (7th mode of Melodic Minor)-Diminished tetrachord, Whole Tone tetrachord on flat 5th.
11. Whole Tone Scale-Whole Tone tetrachord, Whole Tone tetrachord on flat 5th (2nd tetrachord starts on same note on which the first tetrachord ends).
12. Blues Scale-Blues 1 tetrachord, Blues 2 tetrachord on flat 5th (2nd tetrachord starts on same note on which the first tetrachord ends).
13. Lydian Dominant Scale (4th mode of Melodic Minor)-Whole Tone tetrachord, Minor tetrachord on 5th.
14. Locrian #2 (6th mode of Melodic Minor)-Minor tetrachord, Whole Tone tetrachord
15. Major Bebop Scale (Descending)-Diminished tetrachord, Minor tetrachord on 5th, extra root.
16. Minor Bebop Scale (Descending)-Chromatic tetrachord, Phrygian tetrachord on 5th, extra root.
17. Dominant Bebop Scale (Descending)-Chromatic tetrachord, Minor tetrachord on 5th, extra root.
-Camden Hughes