The game's music is done by Tsunku♂ (who also serves as the game's producer), as well as Shinji Ushiroda, Asuka Ito, Yumi Takahashi, and Megumi Inoue. While some music pieces from the original Rhythm Tengoku and Rhythm Heaven (DS) were re-used, Rhythm Heaven Megamix re-uses several music themes from the previous game, Rhythm Heaven Fever. For the prequel versions of older rhythm games from previous titles and for the new rhythm games and remixes in the game, most of the music that Tsunku♂ had composed for them was given a techno-themed motif. This is different from the music styles used in the previous three Rhythm Heaven titles, which in Rhythm Tengoku, Rhythm Heaven (DS), and Rhythm Heaven Fever, the music for those titles was a mix of catchy tunes and vocal songs. In a Iwata Asks interview, Satoru Iwata said; "Making music for the game was difficult, but that's what it was like". Tsunku♂ said; "As with music, to compete with the original work... It's very tricky, but while leaving the theme, the newly created Prequels. In making music for the games (the prequel of Karate Man for example), I'd have a strong feeling for it because it was unexpectedly tough. I am very particular about the game, but no matter how many times I submit a music piece, it doesn't look right... If you make one at Nintendo's request while thinking, some think; The image is a little different, though. The piece for Karate Man submitted for the second time. It was a minor in changes and the guitar was fierce, it's so intense that it's cool! Not the game of the same name that appears in the beginning, though. It is used by those who appear in the final game".
