A bibliographic-information impression word is generated from a bibliographic information segment about selected one of music pieces. An acoustic feature quantity of an audio signal representing the selected music piece is calculated. A feature-quantity impression word is generated from the calculated acoustic feature quantity. A degree of conformity between the bibliographic-information impression word and the feature-quantity impression word is determined. Both the bibliographic-information impression word and the feature-quantity impression word are selected as final impression words when the determined conformity degree is greater than a predetermined threshold value. One is selected from the bibliographic-information impression word and the feature-quantity impression word as a final impression word when the determined conformity degree is not greater than the predetermined threshold value. A signal representing the final impression word or words is stored into a storage in relation to the selected music piece.