AN EXPERT SYSTEM FOR HARMONIZING FOUR-PART CHORALES

We describe a rule-based expert system called CHORAL, that attempts to harmonize four-part chorales in the style of J.S. Bach. The system contains about 300 rules, expressed in first order predicate calculus, and harmonizes chorales using a gcncralc-and-lest method with intelligent backtracking. A substantial number of heuristics are used for biasing the search toward musical solutions. Encouraging results have been obtained.