In any group of 3 consecutive chords, the middle chord is the key and the two chords on either side are the subdominant and dominant chords.

The number of sharps and flats in a key can be determined by the number inside the circle.

Many tunes follow a pattern of falling down clockwise in the circle and proceed back up to the root chord. For example, in the key of G, many songs will go down to E and proceed back up to G. The progression may contain minors or 7ths. An example of this would be G, Em, Am, D7, G.

The circle may easily be memorized by recognizing the pattern of the word BEAD on both the left and right side.

To Transpose a song to another key, simply move each chord the same number of spaces in the circle. For example, to transpose from the key of Bb to the key of D, change all of the chords in the key of Bb to the key of D by replacing existing chords with chords that are 4 spaces to the right.

The relative minor for any key can be easily determined by moving 3 spaces clockwise from the root. For example, count 3 spaces clockwise from C and you will find that the relative minor for C is Am. Count 3 spaces clockwise from D and find that the relative minor is Bm. Likewise, the relative minor for Db is Bbm, etc.