An information processing apparatus is provided which includes a beat analysis unit for detecting positions of beats included in an audio signal, a structure analysis unit for calculating similarity probabilities, each being a probability of similarity between contents of sound of beat sections divided by each beat position detected by the beat analysis unit, and a bar detection unit for determining a likely bar progression of the audio signal based on bar probabilities determined according to the similarity probabilities calculated by the structure analysis unit, the bar probabilities indicating to which ordinal in which meter respective beats correspond.