A double tonic is a chord progression, melodic motion, or shift of level consisting of a "regular back-and-forth motion" in melody similar to Bruno Nettl's pendulum type[ clarification needed] though it uses small intervals, most often a whole tone though may be almost a semitone to a minor third (see pendular thirds). [1]
It is extremely common in African music ("Mkwaze mmodzi"[ clarification needed]), Asian music, and European music, including: [3]
In American music, a rare example of a double-tonic is the spiritual "Rock my Soul" though American popular music began to use the double tonic commonly in the last half of the 1900s, [3] including Beck's " Puttin It Down". [4]
Double tonic patterns may be classified as beginning on the lower ("Sumer is Icumen in", "The Woods so Wild", " The Irish Washerwoman") or upper (most Scottish tunes, passamezzo antico, "Roun' de Corn, Sally", "Shallow Brown", "Mkwaze mmodzi") note and may repeat open endedly, though they are often closed through a tonic close, as in : [5]
Am|G|Am-G|Am||
They are also often varied through a binary scheme ending on the dominant then tonic, as in:
Am|G|Am|E|| Am|G|Am-G|Am||
or,
Am|G|Am|E|| Am|G|Am-E|Am||
A variation of this last progression is the passamezzo antico. [5]