Here is an example of generation of harmonic progression with Opusmodus using chords rules defined with a transition table.
The technique presented here uses the concept of tonal degrees, but it is important to note that as you will see later in this article, this concept can be pushed quite far and quite outside the traditional tonal system.
First, we define some transition rules from degree to degree:
(setf transition
'((1 (4 1) (5 1) (6 2))
(2 (5 2) (4 1))
(3 (4 1))
(4 (5 1) (2 1))
(5 (1 3) (6 2) (4 1))