Conversion of ogg files to mus file format

It seems that mus file extension is used for several audio file types (music), so it is likely at least one of them can be created from an Ogg Vorbis audio. Any modern dedicated audio converter or editor can probably perform ogg to mus conversion, provided it supports mus file type.

Worth mentioning is that Finale music notation program also uses .mus files and can import several audio formats So you may want to try to convert the .ogg file to audio format supported in Finale first, before you try to create a .mus file from it.

Open OGG file    Open MUS file