Information processing device and method, and recording medium

An information processing method, implemented by at least one computer having at least one processor, the method comprising the steps of:

• extracting, using chord progressions extraction means, chord progressions by analyzing waveforms of musical compositions;
• extracting, using first featuring quantity extraction means, a first probability indicating the probability of given chords appearing simultaneously in each of said cord progressions;
• extracting, using second featuring quantity extraction means, a second probability indicating the probability of transition from a given chord to another chord in the chord progression in question;
• and
• calculating first similarities between a chord progression and another chord progression, on the basis of the first probability and the second probability for each chord comprising the extracted chord progressions.

A recording medium which stores a program for causing a computer to execute a chord progression analyzing process comprising the steps of:

• extracting, using chord progressions extraction means, chord progressions by analyzing waveforms of musical compositions;
• extracting, using first featuring quantity extraction means, a first probability indicating the probability of given chords appearing simultaneously in each of said cord progressions;
• extracting, using second featuring quantity extraction means, a second probability indicating the probability of transition from a given chord to another chord in the chord progression in question;
• and
• calculating first similarities between a chord progression and another chord progression, on the basis of the first probability and the second probability for each chord comprising the extracted chord progressions.