1. A non-transitory computer-readable recording medium having stored therein a program causing a computer to execute a category creating process comprising: receiving a piece of music; extracting video image information that is included in the music received at the receiving and decomposing the extracted video image information with respect to each characteristic of the extracted video image information; measuring an appearance time during which a characteristic appears in the music; associating, by referring to a characteristic storing unit which stores the characteristic and a plurality of categories that represent the characteristic in an associated manner, the appearance time measured at the measuring with the plurality of categories which are stored in the characteristic storing unit; and calculating a total time at which each category appears in the music.