If you take inventory of all the songs you know and analyze what your left-hand bass is doing, you’ll undoubtedly discover that most movements are that of fourth intervals. A perfect fourth to be exact.
What is a perfect fourth interval?
The easiest way is to think of it is the 4th tone of any major scale. Once you’ve got them memorized, you’ll just know what a “perfect fourth up from G” is or a “perfect fourth up from Bb.”
For example, the C major scale is:
C D E F G A B C
F is the fourth tone of the scale and therefore a “perfect fourth up from C.”
Once you go to the F major scale, and do the same thing, you’ll arrive at Bb being a “perfect fourth up from F.” Repeat this process and eventually you get this:
C – F – Bb – Eb – Ab – Db – Gb – B – E – A – D – G
This is music’s favorite motion!

Here are the notes organized in what we call the “Circle Of Fourths” (when you go counter-clockwise, the opposite direction of a typical clock’s movement). If you go clockwise, you’re moving up in fifths and that’s why this is also known as the “Circle Of Fifths.”
I prefer calling it the “Circle Of Fourths” because that’s the direction music is usually moving in.
If you circle any three notes going counter-clockwise, you’ve got yourself a “2-5-1” progression, one of the most popular patterns in music. Circle any four notes, and you’ve got yourself a “6-2-5-1” progression, another popular movement.
But just think about it. In songs that you already know how to play (and if you don’t play yet, you will be soon), what chord is most likely to follow, say, an Ab major chord? If you’ve got any experience playing in keys that involve Ab, the next chord up is usually some type of Db chord. And as you can see, they are neighbors on the circle!
Take inventory of the songs you know and see how often the chords move according to this circle. Now, it won’t be 100% because music is vast and includes a variety of different movements, but in most typical songs, you’ll be hard-pressed not to find fourths at work.
Until next time.
Want to learn more about intervals and the circle of fourths? Check out my 300-pg course, “The Secrets To Playing Piano By Ear.”




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