Grading karaoke using commercial musical content is possible. A first sound pitch feature is calculated in every specified time interval from the acoustic signal of a musical piece. A second sound pitch feature is calculated in every time interval corresponding to the specified time interval from the target comparison acoustic signal such as a singing voice signal. In the comparison of the first sound pitch feature and the second sound pitch feature, the similarity between the acoustic signals is calculated. The pitch feature of the chords in the musical piece calculated from the acoustic signal of the musical piece is set as the data at hand. For example, grading karaoke using the commercial musical content provided on a compact disc (CD) becomes possible.
SOUND PROCESSOR, SOUND PROCESSING METHOD, PROGRAM, ELECTRONIC DEVICE, SERVER, CLIENT DEVICE, AND SOUND PROCESSING SYSTEM