A tetrachord is a four note scale. Music theory doesn’t have to be scary. A tetrachord is just four notes.
The majority of Western scales have 8 notes, so a tetrachord can be thought of as half of a scale.
Just as an interval is a basic building block in music, a tetrachord is a (larger) building block of a scale. Two tetrachords combine to form a scale.
The two tetrachords are usually separated by a whole-step or half-step. For a few of the scales, there is no interval in between the two tetrachords.
Gary Burton teaches that there are basically ten important scales in jazz.
I’ve chosen 6 more that are also important, bringing the number to 17 scales.
ALL of these scales can be broken down into tetrachords, although if you have a 9 note scale like a diminished scale, you’ll need to repeat the starting note after playing two tetrachords.
Why are tetrachords important? If you are trying to learn many scales, breaking them down into 4-note chunks (tetrachords) is an excellent idea.
Jimmy Lawrence is a former student of mine who is in grad school for music at Azusa Pacific University. He used to teach all 12 major scales to LITTLE kids on the piano. He used tetrachords to teach scales because the whole-steps and the half-steps are easy for young students to recognize.
Learning 17 different types of scales can be a little overwhelming at first. Learning the 17 scales in tetrachords can help.
Here’s a more in-depth look at the tetrachords.
This is how you can use these tetrachords to make scales.
I actually got some of these ideas from Charlie Austin, adapting them to my own teaching.
I don’t understand why more music teachers don’t teach scales with tetrachords. Tetrachords are an excellent way to break scales into manageable chunks. Scales are really easy to figure out when all you have to remember is two tetrachords instead of 8 notes.