Maintain Separateness and Complementarity of Rhythm

1. Do not halt motion in both voices at the same time except at strong, conclusive cadences.

2. Although “halting on weak beats” should be avoided (see well-formedness guidelines on rhythm)—it is ok to halt in one voice while another carries the motion, in order to maintain the rhythmic separateness of voices

3. Make sure each phrase has a good balance of oblique, contrary, and parallel motion.

4. It’s ok for the voices occasionally to move in similar rhythm in order to provide contrast or relief from their constant separateness: the goal of this guideline is to produce overall separateness, not constant separateness.

Sufficient Similarity of Character and Style

1. Generalize the note values and rhythm-types (dotted values, triplets, etc.) used in one voice, and make sure they are used in the other.
2. Reduce, re-use, recycle: distinctive rhythmic cells should not be too great in number or too various. Re-use and recycle them in the second voice if they occur in the first.
3. Pay attention to other aspects of style and make sure the voices don’t contradict – (but this guideline is 90% accomplished simply by maintaining clear harmonic and melodic progression as per the well-formedness guidelines!)