The circle of fifths is a conceptual diagram which serves as an aid in memorizing key signatures and helps us understand the relationships between the various keys. The twelve key signatures—enharmonic keys counting only once—are arranged in a circular clock-like fashion. The key of C major with no sharps or flats is in the 12 o’clock position. Proceeding in clockwise fashion, the keys are arranged by ascending fifths—G major (one sharp), D major (two sharps), A major (three sharps), and so on. Proceeding in counterclockwise fashion, the keys are arranged by descending fifths—F major (one flat), B♭ major (two flats), E♭ major (three flats), and so on. Take note of the six enharmonic keys at the 5, 6, and 7 o’clock positions.
