Well if i remember, marble madness was one of the first games that came out on Amiga, therefore at least a couple of years before the .mod format was estabilished; since the conversion was made from Electronic Arts, i expect the music files to be maybe in .smus but i might be wrong; there is a web site called ExoticA where game musics are stored in their original format, you can try to give a look in there:
ExoticA music archiveSaimon69
