Picture of the C and A keys of guitar chords

Playig guitar and singing is one of the things I sometimes like to do. I also love mathematics. I mostly figured out the chords by myself since I had no formal training.

I leant that you could write all the keys as a group of 6 chords which you can substitute with the corresponding chords of another key when transposing between keys.

Have a look at http://guitarsecrets.com/lessons/modulation.htm for a description of the keys.

For example: In the above picture you can see the arrangement of chords for the keys of C and A.

For the key of C, the chord C is known as the tonic chord since it gives the key note/ first note of the scale. The chord G7 is called the dominant chord, F the sub dominant. These are the major chords of the key. The minor chord Dm is called the supertonic, Am is called the sub-mediant and E7 is called the Major sixth. Don't take my word on it, look for yourself, as I am not an expert.
http://www.dancingcat.com/skbook7-glossary.shtml#SecondG

While using these 6 chord key groupings I discovered that they can be linked together. See it in my next post.