Square Enix are going all out on differentiating both versions of the game.
Square Enix’s strategy with Dragon Quest 11 is fascinating- they are bringing the game to 3DS and PS4, and given the vast difference in the two platforms, they are essentially developing the same game twice, tailored to each system’s unique strengths. Dragon Quest 11 on the PS4 and 3DS share the same premise, story, characters, and name- but they are entirely different games otherwise.
These differences will extend to the games’ soundtracks as well. While they will have the same musical tunes, different arrangements will be used for the PS4 and 3DS versions of the game, according to composer Koichi Sugiyama (via Nintendo Everything). Sugiyama did not comment on the Nintendo Switch version, and whether it will have its own arrangements, or whether it will use the ones from the PS4 or 3DS versions.
Dragon Quest 11 is due out on Nintendo 3DS, Nintendo Switch, and PS4 in Japan this year; a release in the west has been discussed, but not officially confirmed yet.