I m,ade a simple menu music replacement. I put together an ogg file of crimson tide theme with a little speech in the middle of the file. The speech starts after 2.10 minutes so you dont have to hear the speech every time you start the game. You would have to linger in the menu for a while to hear it.
You can make a folder structure for use with jsgme. Put Menu_Master LOOP.ogg into call it what you want\Data\Sound\Music and put call it what you want folder in your MOD folder inside sh4.
You can use it for what ever mega mod you use or with stock sh4. I use it for fotrs. The menu in fotrs is excellent and no really need to change music but only if you want a change.