Hi; i'm actually thinking about whether there is a relation between the chance of a given chord to (fixedly, lets say) bear a given melody and the size of the intervals defined by the downward counterpoint of the given melody; for instance, a certain melody starting at III has a downward cp involving a bass-line through some of the scale degrees VI-V-IV-I: that is, the interval size doesn't goes beyond a 3rd, let's say; on the other hand, the whole melody is bore by the chord I64.
As the melody line changes, so it does the downward cp and in some cases the bearing of the melody by the fixed chord former chord seems to not hold anymore beyond a given measure, etc.
Greetings.