Showing papers by "Kemal Ebcioglu published in 1986"

An Expert System for Harmonizing Four-Part Chorales

Abstract: Quite a few trends in algorithmic composition today are based on a streamlined formalism, for example, in the form of random generation of note attributes using elegant statistical distributions (Xenakis 1971), terse and powerful formal grammars (Jones 1981), elegant mathematical models (Kendall 1981; Vaggione 1984), or generalizations of serial composition procedures (Laske 1981). The economy and elegance of the formal representation underlying these musical styles (which are not in the least less respectable than traditional styles of music), may often have an aesthetic appeal in and of themselves. On the other hand, traditional music and most of modern music, which are usually composed without a computer, do not seem to permit such economical representations. In the traditional style, the typical basic training the composer has to go through in harmony, strict counterpoint, fugue,

An expert system for chorale harmonization

Abstract: We have designed an expert system called CHORAL, for harmonizing four-part chorales in the style of J.S. Bach. The system contains over 270 rules, expressed in a form of first order predicate calculus, for representing the knowledge required for harmonizing a given melody. The rules observe the chorale from multiple viewpoints, such as the chord skeleton, individual melodic lines of each voice, and the Schenkerian voice leading within the descant and bass. The program harmonizes chorales using a generate-and-test method with intelligent backtracking. A substantial number of heuristics are used for biasing the search toward musical solutions. Examples of program output are given in the paper. BSL, a new and efficient logic programming language which is fundamentally different from Prolog, was designed to implement the CHORAL system.