Generating a melody based on symbiotic evolution for musicians' creative activities

When musicians are asked to create music with a special theme or for a particular use, it is important for them to meet the client's demands and express their original creativity. As this task is a little more difficult than their free creative activities, an automatic music composition system may support them. Requirements for the system are the ease of expressing the musicians' intention and the shortness of the processing time. In this paper, a scene where musicians create a song using an automatic composition system is assumed, and a method of generating a melody for the system is proposed. In the proposed method, two kinds of sensibility models for melody are induced from the existing music. A melody template is generated on the basis of those models using a symbiotic evolution algorithm. A melody is completed by determining pitch of each note in the melody template. The results of the subjective evaluation experiment show the effectiveness of the proposed method. In addition, two case studies of works with professional musicians are also presented. The results of questionnaire surveys show that the composed music reflects the musicians' intentions and is not inferior to music composed by human composers.