An apparatus for determining a lyric importance level, comprising: a memory; and a processor executing instructions stored in the memory to: acquire lyric information, the lyric information identifying: lyrics of a song; and lyric location information indicating locations of the lyrics within the song; acquire melody section information, the melody section information identifying: melody sections of the song; melody section importance levels corresponding to the melody sections; and melody section location information indicating locations of the melody sections within the song; identify, based on the lyric location information and the melody section location information, one or more melody sections corresponding to a first subset of the lyrics and one or more melody sections corresponding to a second subset of the lyrics; and determine, based on the melody section importance levels, a first lyric importance level of the first subset and a second lyric importance level of the second subset, wherein the processor further executes the instructions to: identify designated subsets of the song, the designated subsets comprising: the first subset, if the first lyric importance level is greater than or equal to a predetermined importance level; and the second subset, if the second lyric importance level is greater than or equal to the predetermined importance level, the apparatus being characterised in that, while reproducing the song, the processor further executes the instructions to: gradually display the lyrics on a screen, and display, if the designated subsets include the first subset, a first image on the screen; and display, if the designated subsets include the second subset, a second image on the screen, wherein the first image and the second image are displaced or deformed on the screen in accordance with the beat of the song. a memory; and a processor executing instructions stored in the memory to: acquire lyric information, the lyric information identifying: lyrics of a song; and lyric location information indicating locations of the lyrics within the song; acquire melody section information, the melody section information identifying: melody sections of the song; melody section importance levels corresponding to the melody sections; and melody section location information indicating locations of the melody sections within the song; identify, based on the lyric location information and the melody section location information, one or more melody sections corresponding to a first subset of the lyrics and one or acquire lyric information, the lyric information identifying: lyrics of a song; and lyric location information indicating locations of the lyrics within the song; lyrics of a song; and lyric location information indicating locations of the lyrics within the song; acquire melody section information, the melody section information identifying: melody sections of the song; melody section importance levels corresponding to the melody sections; and melody section location information indicating locations of the melody sections within the song; melody sections of the song; melody section importance levels corresponding to the melody sections; and melody section location information indicating locations of the melody sections within the song; identify, based on the lyric location information and the melody section location information, one or more melody sections corresponding to a first subset of the lyrics and one or more melody sections corresponding to a second subset of the lyrics; and determine, based on the melody section importance levels, a first lyric importance level of the first subset and a second lyric importance level of the second subset, wherein the processor further executes the instructions to: identify designated subsets of the song, the designated subsets comprising: the first subset, if the first lyric importance level is greater than or equal to a predetermined importance level; and the second subset, if the second lyric importance level is greater than or equal to the predetermined importance level, the first subset, if the first lyric importance level is greater than or equal to a predetermined importance level; and the second subset, if the second lyric importance level is greater than or equal to the predetermined importance level, gradually display the lyrics on a screen, and display, if the designated subsets include the first subset, a first image on the screen; and display, if the designated subsets include the second subset, a second image on the screen, wherein the first image and the second image are displaced or deformed on the screen in accordance with the beat of the song.