I know the music crashes the game sometimes, so what is the best way to replace the music? I got the soundtrack, but there are a lots of files in there. If I get one track on repeat mode the rest will not be played.

What are your' settings? Maybe some good free replacement music? Some good fantasy mp3 that would really suit Master of Magic? Some soundtracks from Jamendo perhaps?

I have never heard this. Do you have a source?

Well, not exactly. But for instance here it says htat is slows down the game (which is obvious).
[url=https://www.dosbox.com/wiki/GAMES:Master_of_Magic]https://www.dosbox.com/wiki/GAMES:Master_of_Magic[/url]

I personally have seen that when the game stutters it sometimes crashes. But for me it really does not happen unless I am alt tabbing. Still you can search yourself on google how many people have resolved their problems when they disabled music.

Enable cycles=max and core=dynamic in DOSbox to get rid of any performance issues. The game takes a moment to load when the best sound option, MIDI, is selected. However I am in favor of muting the music entirely and putting your own MP3s on in the background. The game's music just repeats and repeats.

I tried to add this info to the official DOSbox wiki site but it has some impossible password.