I'm not sure I have the answer you're looking for. If I understand your question, you would like to know how to use the circle of fifths in your musical compositions. Let's face it, playing or composing a song in one key is nice, but you can spice things up a bit by changing the key mid song. You hear it done quite often. I'll skip all the stuff about how it's easy to figure the key signature using the circle of fiths and go right to the trick.

A simple way to change keys in a song is to convert your tonic chord (I) to a dominant 7th and use it as the V7 of the new key. For example, if you want to go from the key of G to the key of C, change the G chord to a G7. This leads naturally to the key of C. Actually, you really don't have to convert the chord to the dominant seventh, it just seems to be a more natural transition. You can do this on any chord in the scale of the key you're in; however, it's often best (but not necessary) to convert a minor chord to a major chord first.

A common progression, A7 to D7 (we just changed the I chord to a V7)changes from the key of D to the Key of G. Looking at the circle of fifths you can see the key of G is back one key from D. Often composers will do a quick progression several keys back. Try playing A7, D7, G7, C. Each key is a 5th back from the last.

Hope this helps you with your compositions.

Wiley