i know this isnt quite what you asked but just get romis addmusic and then copy cmd into the addmusic folder (or make a batch file like this
like that ^)
and place the song you want in the respective folder and in this ini file addmusicini
then you type the txt files name in the level slot you want to use. same for overworld. you enter it in like this
20=megamari cirno.txt (now for this, if the song has a space in its name, well, add a space
then in the command prompt, type addmusic.exe romname.smc then hit enter, now after you insert, you get a msc file which you keep with the rom at all times so when you open lunar magic, you can see whats there.
lastly, to change title music with romis, you need to either hex edit or just at the top of the ini file, youll see titlescreen=01 or something like that, change it to one of the overworld themes like 0A and then insert the song you want in that slot.