Because the Array system is isomorphic, any given chord, scale, or song, no matter how complex, can be played in any one of the 12 keys immediately after the player learns to play it in one key. Because it is unimorphic, common chords tend to fall close together. In the key of C, for example, the F and G major chords can be played by moving the C major chord shape one octave group to the left or right. The same applies to Em, Am, and Dm. The minor chord shape is easier to play with the left hand, while major chords are easier to play with the right hand.