https://www.pcgamer.com/dragon-quest-11-orchestral-music-mod/

Unlike the last grand console adventure in the Dragon Quest series, the music in Dragon Quest 11: Echoes of an Elusive Age is entirely synthesized. Some Dragon Quest enthusiasts were disappointed by this perceived step backwards, especially since Dragon Quest 8 on PS2 had a lushly orchestrated soundtrack. If you're among the disappointed, never fear: a mod has been released that lets you replace all the music in DQ11 with pre-existing orchestral versions of the songs.

"The goal of this mod is to provide the proper auditory experience that is deserving of this masterpiece of a game by applying all available orchestral variants of the songs present in the game, as composed by Koichi Sugiyama and performed by the Tokyo Metropolitan Symphony Orchestra," reads the official description.