excellent piece of music, to my ears. i consider myself a musician (amateur composer?) with an adequate knowledge of theory. even though the notion of a confined search-space was already priming me for a possibly less continuous melody, the melody still struck me, even emotionally. the brute-force method, to generalize from a single example, seems to be excellent (when well-constrained) for writing novel chord progressions. perhaps if you use the second chord of each sequence as the first chord of a new sequence, afterward piecing them together, you could increase continuity even further. i think this piece, however, might say more about the qualities that would satisfy your goals (IOW, a solution to the problem) than the search-space you covered, perhaps? to clean up this particular example, perhaps one might more clearly define what qualifies as a solution in the first place? for example, how "good" did one phrase need to sound before it was acceptable?