Learning the Circle of Fifths. This lesson teaches how to read and use the circle of fifths by breaking it into two separate circles . One that is called the modified circle of fifths which isolates the musical keys that include sharps notes, and one that is called the circle of fourths which isolated the musical keys that include flats. There are also some very useful tips on how to memorize and use the two circles. Follow along with the video at https://youtu.be/rIduGCEsAcI