A computer model of blues music and its evaluation

This paper describes a new algorithm that composes blues melodies to fit a given chord sequence. It comprises an analysis stage followed by a synthesis stage. The analysis stage produces a Markov model composed of zero, first‐, and second‐order transition tables covering both pitches and rhythms. In order to capture the relationship between harmony and melody, a set of transition tables is produced for each chord in the analyzed songs. The synthesis stage uses the output tables from analysis to generate new melodies; second‐order tables are used as much as possible, with fall back procedures to lower‐order tables. Some constraints are encoded in the form of rules to control the placement of rhythmic patterns within measures, pitch values for long duration notes and pitch values for the start of new phrases. The model was evaluated by a listening experiment; results showed that listeners were unable to reliably distinguish human from computer composed melodies.