Circle of Fifths
A method of modulation that begins on a tonic and moves to the dominant of that tonic, which is the fifth tone of the scale. From there the music moves to the dominant of the previous dominant, that is the fifth tone from the fifth tone of the original tonic. The music thus proceeds until the original tonic is again reached. In the key of C major, the circle of fifths would proceed as follows: C, G, D, A, E, B, F#, C#, G# (Ab), D# (Eb), A# (Bb), F, C.