here you go mate, i posted this somewhere else but should help.
DEAR ALL
i like many others toiled away trying to get mp3's to show up in the game on my PS3. here are a few things i did and now have a full on library to choose from...
instead of transferring music / chants using a usb key, put the chants and music files for your menu's on to a CD and rip them directly on to your PS3. i used windows media player instead of itunes as i didn't know how the mp4 would react. badly i reckon!
before ripping the music and chants go to your system settings (the screen which comes up when you have no game inserted in the console) and scroll down to music settings. change the import setting from acc to mp3 at a speed of 128. my console was set to acc so it's well worth double checking.
edit all the track / chant names to make them easier to find when in the game to save having to listen to all the files before you assign. also, it's just better if you get the artist and track name come up when a song starts

it might be worth doing this on your pc before making the CD to rip.
when making the playlist it MUST be called KONAMI_PES and it MUST NOT have any spaces at the end. one way of being able to tell if it is correct is, when changing the name of the playlist, press start after entering the title. the cursor will move one to the right automatically so press back space (L1) to remove the space, and hold the start button. when the title of the playlist appears in the playlist information it should be surrounded by a box which should be tight to the "S" at the end of the title. it is quite noticable if there is a space at the end of the title.
on my console i ripped the music files last, after the chants, and for some reason it decided to put some music files in my folders with the chants in. i suggest ripping your music files before your chant files.
i hope this helps if anyone was having trouble....