Orpheus: Automatic Composition System Considering Prosody of Japanese Lyrics

We present an algorithm for song composition using prosody of Japanese lyrics. Since Japanese is a “pitch accent” language, listener’s apprehension is strongly affected by the pitch motions of the speaker. For example, the meaning of Japanese word “ha-shi” changes with the pitch. It means “bridge” with an upward pitch motion, and “chopsticks” with the motion inversed. A melody attached to the lyrics cause an effect similar to the pitch accent. Therefore we can assume that pitches of Japanese lyrics give constraints on pitch motions of the melody. Furthermore, chord progression, rhythm and accompaniment give constraints on the transitions and occurrences of the melody notes. If a certain melody for the lyrics were obtained, the melody would satisfy these constraints. Conversely, we can compose a song by finding the melody which optimally meets the condition.