Automatic composition of happy melodies based on relations

To compose some happy melodies which have hierarchical structures, this paper proposes an automatic melody composition algorithm based on relations. First, various types of melody structure are formalized and saved into a database, so the melody structure form preferred by a user can be elected by human-computer interaction. Second, some sequences of trunk-note and several algorithms of splitting note are constructed by means of the pitch interval features of happy melody, and the theme phrase of happy melody is generated by splitting some trunk notes of the trunk-note-sequence. Third, several types of operators for developing the theme phrase, which include pitch offsetting, phrase inversing and repeating-developing, are constructed using relationship methods. Finally, under the guidance of the elected melody structure, some happy melodies of songs are produced automatically by the interreaction of the theme phrase and these operators. Experimental results demonstrate that this algorithm can make the obtained melodies have musically meaningful structures, and it is not easy to distinguish these machine-generated melodies from human-generated melodies.