"Art begins with craft, and there is no art until craft has been mastered."
These attempts to describe what has been thought to "work" take the form of rules: rules for melodic movement, rhythmic values, vertical relations between notes, etc. But the word "rule" has sometimes led to an impression that there is something oppressive about this study. Maybe it would be better to speak in terms of "recipes." One does not feel constrained by a recipe; a recipe is merely a helpful guide to achieving the desired effect. Similarly, the "rules" of counterpoint can be considered to be parts of a recipe by which one can achieve a certain musical effect. You can break the rule if you want a different effect, just as you can substitute asparagus for the spinach in a spinach omelette (but the result will not be a spinach omelette). If you test the work of known composers using appropriate style rules you'll find that the rules are sometimes broken - but they are broken with intent and with understanding.
When doing exercises, as opposed to real composition, it's actually more fun to just accept the rules in a strict legal sense. There is a benefit in submitting yourself to a strict teacher: you gain in facility even when doing a purely technical exercise that is not directly applicable to real composition. In his own book on counterpoint Walter Piston objected that traditional methods of teaching composition merely put forth directions for writing music, and those directions may not be applicable ten years hence. However, most great composers have studied archaic directions for writing music, and they did so for the sake of increased understanding and skill. When Mozart studied with Padre Martini he was practicing not the type of music he would himself write, but the liturgical vocal style of 200 years earlier. His teacher did not show him how to compose like Mozart, but developed his skill in part writing by holding him to strict and partly irrelevant standards in his exercises. Not only Mozart, but Haydn, Beethoven, Brahms, and others studied strict counterpoint of the type taught by Johann Fux and loosely based on the music of the 16th century.
Today we benefit from a human teacher when discussing subtleties and affects, but no human can match the computer when it comes to tireless exactitude in examining purely technical aspects of your work. Counterpointer will not by itself make you a great composer, but it will make you think about what you are doing. The computer offers no condemnation for your errors and no sympathy whatsoever for your hard effort. It has no thought for your feelings. The computer will be content to work with you for years if asked, and it will take no offense if it is serving only as the assistant to a human instructor.
Jeff Evans
©2011 Ars Nova Software, LLC