<P>PROBLEM TO BE SOLVED: To calculate feature quantity of piece of music corresponding to features of each piece of music while using the review including information other than the features of the piece of music. <P>SOLUTION: A plurality of feature phrases composed of combination of a plurality of words are predetermined as the one showing the features of piece of music, the feature quantity of piece of music is calculated as a vector using a TF-IDF value calculated based on appearance frequencies of each characteristic phrase in review data as an element and the feature quantity is considered as an index showing the feature of each piece of music. Thus, the feature quantity of the piece of music is calculated while excluding comments other than the features of the piece of music as much as possible even when there are comments other than the features of the piece of music by using a feature phrase composed of combination of the plurality of words. As a result. the feature quantity of the piece of music calculated based on the appearance frequencies of the characteristic phrase is matched to impression (sensibility) felt when the piece of music is actually appreciated with sufficient accuracy. <P>COPYRIGHT: (C)2008,JPO&INPIT 
PIECE OF MUSIC FEATURE QUANTITY ARITHMETIC UNIT AND PIECE OF MUSIC RETRIEVAL SYSTEM