| 摘要 |
PROBLEM TO BE SOLVED: To automatically compose a chorus on the basis of rhythms of the lyrics.SOLUTION: A method for automatically composing a chorus from the Japanese lyrics includes: a step of determining reading and a rhythms of a text from inputted Japanese lyrics; a step of determining a chord progression; a step of determining a rhythm of a melody; and a melody generation step of generating the melody in accordance with a predetermined composition condition. In the melody generation step, an occurrence probability of the melody is approximated by a product probabilities of transition between neighboring pitches, the probability of transition between neighboring pitches is approximated by a combination of probabilities for each composition condition, a melody is regarded as a path of lattice points formed from the rhythm determined by a rhythm determination section and pitches, and a likelihood maximum path is determined by dynamic scheduling. In the melody generation step, a probability to determine a constraint based on a musical theory between melodies of voice parts is used to determine an occurrence probability of a melody of a certain selected voice part as a conditional probability defining a melody of at least one of other voice parts as a condition. |
